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Biomedical subjects

G Larsen

Publications and source records attributed to G Larsen.

18 recordsLinked to original sources
PubMed1991

Partial hydatidiform mole with subsequent trophoblastic tumor; a case report.

A case of partial hydatidiform mole revealed by genetic marker analysis one maternal and two paternal chromosome complements. Levels of serum human chorionic gonadotropin were persistently elevated during follow-up. Avillous curettage specimens prior to chemotherapy were morphologically suspicious for gestational choriocarcinoma. It is still uncertain whether the risk for gestational choriocarcinoma preceded by partial mole exceeds the risk related to non-molar abortions. Careful follow-up with serial serum human chorionic gonadotropin levels is required to detect persistent disease.

Adult↗
PubMed1991

Incidence of molds and mycotoxins in commercial animal feed mills in seven midwestern states, 1988-1989.

A total of 82 feed manufacturers located within seven midwestern states (Iowa, Nebraska, Minnesota, Illinois, Indiana, Ohio, Michigan) participated in a survey of mold and mycotoxin contamination of corn. Samples were submitted from a composite of the grading samples taken from each incoming load of corn. The survey was initiated in July 1988. During the 12-mo period, moisture content of the corn samples upon receipt at the laboratory ranged from 10.5 to 13.3%. The greatest variation occurred in the springtime. Iowa's corn samples were driest (11.2%), and samples submitted from Ohio were wettest (12.8%). Mold counts averaged 2.63 x 10(4) per gram during the year. The predominant mold found was Fusarium sp. Samples were checked by black light and averaged 25.4% positive during the period. When assayed for mycotoxins, 19.5% of the samples were positive for at least one of the following: aflatoxin, zearalenone, T2 toxin and deoxynivalenol (vomitoxin). Aflatoxin and T2 toxin made up the majority of these samples containing toxin. The highest incidence of mycotoxin-contaminated corn (48%) occurred in samples submitted in July of 1988. Over the 12-mo period, the highest mycotoxin contamination occurred in Iowa, Illinois and Michigan. When samples were subjected to 90% relative humidity and 32 degrees C, an average of 3.9 d was required for mold growth to appear. After incubation, 24.7% of the samples contained one of the four toxins. The data indicate that mold and mycotoxin contamination of mixed samples of corn is widespread, even in the midwestern corn belt of the U.S.

Aflatoxins↗
PubMed1991

Hydatidiform mole and fetus with normal karyotype: support of a separate entity.

Repetitive hydatidiform mole was observed in four pregnancies. The pregnancies presented with heavy bleeding and vomiting, but the post-evacuation courses were uncomplicated, with rapid regression of serum hCG levels. Cytogenetic investigations, analyses of restriction fragment length polymorphisms, and flow cytometry in three pregnancies were consistent with diploid, biparental conception as the origin of fetal tissue and molar and nonmolar villi. In one pregnancy, the analyses of cytogenetic markers suggested the coexistence of two different cell lines of dizygotic, biparental origin, whereas DNA analysis was consistent with a single conception. With incomplete genetic information, a hydatidiform mole with coexistent normal fetus is generally considered to result from dizygous twinning comprising an androgenetic complete mole and a normal conception. In the present gestations, the results based on several techniques applied on numerous samples from different tissues render this possibility unlikely. Some of the contradictions between histologic and cytogenetic classifications of hydatidiform mole may be explained by diploid, biparental partial mole, which seems to constitute a separate subgroup within hydatidiform mole. Following chorionic villus sampling or amniocentesis, continued pregnancy may be considered, depending on prenatal diagnosis including genetic marker analysis.

Adult↗
PubMed1990

Lymphocyte subpopulations in patients with cervical intraepithelial neoplasia.

Quantitation of T-lymphocyte subsets and natural killer cells in peripheral blood of 16 patients with cervical intraepithelial neoplasia and 15 controls with normal cervical cytology was performed using specific monoclonal antibodies and flow cytometry. No differences were observed in T-helper lymphocytes, T-suppressor/cytotoxic lymphocytes, Th/Ts cell ratios, or natural killer cells. The results indicate that disturbances of the cell-mediated immune response, observed in patients with invasive cancer of the cervix, are secondary to the disease and of no significance in the initiation of cervical cancer.

Female↗
PubMed1990

Laser conization: follow-up in patients with cervical intraepithelial neoplasia in the cone margin.

Combination laser conization was performed in 469 patients for the treatment of cervical intraepithelial neoplasia (CIN). In 58 cases (12.4%), CIN was located in the margins of the cone. Fifty-one patients with involvement of the margins were evaluated by cytologic examination, using the Ayre spatula and the Cytobrush, and by cervical biopsy and endocervical curettage (ECC). In six cases, the histologic evaluation was positive, and in three of these cases, the cytology was positive too. Hysterectomy was performed in five cases, but in only one case was a significant lesion demonstrated in the uterus. These results justify expectant, conservative management of patients treated with combination laser conization. Follow-up based on colposcopy and cytology seems sufficient.

Aged↗
PubMed1989

Experimental data on in vitro fibre solubility.

Different types of natural and synthetic fibres have been subjected to systematic solubility tests in vitro in a physiological solution at 37 degrees C. Both closed-system and open-system experiments were carried out. Atomic absorption spectrometry of the filtered fluids showed characteristic differences of solubility. Plastic fibres are practically insoluble. In contrast to glass fibres, the solubility of asbestos fibres is low. Sepiolite and wollastonite are of moderate solubility. The results were confirmed by scanning electron microscopy. Kinetic studies and extensive solubility tests led to a new exponential expression which describes the dissolution process in a closed system better than the square-root time laws often used. Moreover, this exponential model provides a new method of distinguishing between different materials by means of their initial rates of dissolution.

Asbestos↗
PubMed1988

The results of cryosurgery for cervical intraepithelial neoplasia.

During 4 years, 1980-1984, 197 patients were treated for CIN II and CIN III by cryosurgery. Included were 62 patients with endocervical involvement (positive ECC). The cure rates of a single cryosurgical treatment were lowered significantly by increasing grade of CIN and by endocervical involvement. The factors influencing the cure rates of cryosurgery are discussed in relation to the results obtained in the present study. The most important step in treatment of patients with CIN by conservative methods seems to be the pretreatment evaluation and not the method of treatment. Despite the fact that we achieved good results in treating patients with CIN II and endocervical involvement (cure rate: 88.9%) it is our opinion that endocervical involvement should contraindicate conservative procedures. The potential risk of overlooking invasive disease among these patients should always be kept in mind. Careful pretreatment evaluation in patients undergoing cryosurgery is mandatory, or else this excellent method would be brought into discredit.

Adult↗
PubMed1988

The prognostic and therapeutic value of second-look laparotomy in advanced ovarian cancer.

Of 267 patients with ovarian cancer FIGO stages III and IV, 157 underwent second-look laparotomy after combination chemotherapy consisting of cis-platinum and cyclophosphamide with and without doxorubicin. At second-look operation 45% had macroscopic tumour, 15% microscopic tumour, and 40% complete pathological response. Survival 3 years after second look was: complete pathological response 74%; microscopic disease 24%; visible tumour less than 1 cm 28%; visible tumour greater than 1 cm 17%; negative cytology 59%; and positive cytology 18%. Of the patients with macroscopic tumour, 29% had all visible tumour removed at second look. Three-year survival for these patients was about 45%.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Pharmacokinetics and thrombolytic properties of deletion mutants of human tissue-type plasminogen activator in rabbits.

The following mutants of human tissue-type plasminogen activator (t-PA) were constructed by deletion mutagenesis of t-PA cDNA, expressed in Chinese hamster ovary cells and purified to homogeneity: (a) t-PA-delta FE:t-PA lacking both the fibronectin fingerlike (F) domain and the epidermal growth factor (E) domain, (b) t-PA-delta FE1X:t-PA-delta FE with the glycosylated 117Asn mutagenized to Gln, and (c) t-PA-delta FE3X:t-PA-delta FE with the three known glycosylated Asn residues replaced by Gln. The mutant and natural t-PA (Mel-t-PA obtained from melanoma cell culture) were infused intravenously for four hours into rabbits with jugular vein thrombosis at doses ranging between 0.12 and 0.75 mg/kg. Fifty percent thrombolysis, determined by interpolation, was obtained with 0.4 mg/kg Mel-t-PA, 0.37 mg/kg t-PA-delta FE, 0.2 mg/kg t-PA-delta FE1X, and 0.40 mg/kg t-PA-delta FE3X. These infusion rates resulted in plateau levels of t-PA antigen in plasma of 0.055, 2.1, 0.6, and 0.5 micrograms/mL, respectively. At 50% lysis, the residual fibrinogen 30 minutes after the end of the infusion was 100%, 81%, 100% and 85% of baseline, and the residual alpha 2-antiplasmin was 82%, 55%, 85%, and 90%, respectively. These results indicate that t-PA-delta FE1X and t-PA-delta FE3X have a specific thrombolytic activity and fibrin specificity comparable to that of Mel-t-PA. t-PA-delta FE has a comparable specific thrombolytic activity but a lower fibrin specificity than Mel-t-PA. After the end of the infusion, t-PA-related antigen disappeared from plasma with an initial t1/2 of four minutes for Mel-t-PA, 25 minutes for t-PA-delta FE, 42 minutes for t-PA-delta FE1X, and 14 minutes for t-PA-delta FE3X. It is concluded that t-PA can be modified by deletion mutagenesis to yield variants with a markedly longer half-life in the blood. Some of these variants have a specific thrombolytic activity and fibrin specificity similar to that of natural t-PA. These variants may be useful to identify the structures in t-PA responsible for its clearance, specific thrombolytic activity, and fibrin specificity in vivo.

Animals↗
PubMed1975

Structural X-chromosome abnormality in a female with gonadal dysgenesis.

A patient with gonadal dysgenesis and 46 chromosomes is described. In the inactive X chromosome there seems to be a deletion of the short arms and an insertion of heterochromatin in the long arms. The most probable mechanism to explain this structurally abnormal X is a pericentric inversion, with breakage and union having occurred in the centromeric heterochromatin of the short arm and in band q23 of the long arm. An amplification of the centromeric heterochromatin left in the short arm is also supposed.

Adult↗