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Biomedical subjects

A Frost

Publications and source records attributed to A Frost.

At least 55 records · Page 3Linked to original sources
PubMed1994

Preoperative parathyroid localization: prospective evaluation of technetium 99m sestamibi.

The utility of preoperative parathyroid localization remains controversial. The gold standard for identification of abnormal parathyroid glands is exploration of the neck by an experienced surgeon. However, both for the experienced and less experienced surgeon, it may be desirable to localize the abnormality before surgery. Such a study would not only direct the surgeon to the site of the lesion but also would help reduce unnecessary dissection, the number of negative explorations, and operative anesthesia time. Unfortunately, currently used noninvasive techniques including ultrasonography, thallium-technetium subtraction, computed tomography scan, and magnetic resonance imaging have had only limited success (35% to 78%) in demonstrating abnormal parathyroid glands. Thirty patients with proven hyperparathyroidism were enrolled to compare a new imaging agent, technetium 99m sestamibi, as an alternative to thallium 201 for subtraction scintigraphy with technetium 99m pertechnetate. Only 14 of 30 patients operated on at George Washington University underwent an identical surgical approach (exploration of all four glands) and had complete preoperative calcium and parathormone levels, postoperative calcium levels, and total time of surgical procedures to formulate the basis of this report. The remaining 16 had their surgeries at other institutions. A surgical approach different from that used at George Washington University and unavailability of postoperative calcium levels and times of surgical procedures from these institutions necessitated deletion of these 16 patients from this report. Technetium 99m sestamibi-technetium 99m subtraction scans accurately localized the abnormal parathyroid gland in 13 of 14 patients, as compared with only 9 of 14 thallium 201-technetium 99m pertechnetate subtraction scans. These results support technetium 99m sestamibi scanning as the superior modality for preoperative parathyroid localization.

Adult↗
PubMed1993

Potential synergism between wheat bran and psyllium: enhanced inhibition of colon cancer.

In this study we compared the influence of high fat (20% w/w) diets that combine low levels of calcium (0.18% w/w) and low (1% w/w), medium (4% w/w) and high (8% w/w) levels of dietary fiber from wheat bran (WB), with high (8% w/w) levels of dietary fiber from psyllium (PS) alone or in various combinations with WB, on the induction of colon tumors in Fischer-344 rats following exposure to azoxymethane (AOM). The rats were fed the experimental diets for 2 weeks, and then were given two s.c. injections of AOM (15 mg/kg body wt./week). Twenty-three weeks following the first injection of AOM, the incidence of colon tumors in the different dietary groups (12 rats/group) was compared. The results clearly showed that by increasing the dietary fiber concentration of WB from 1 to 8% significantly reduced the number of colon tumors/group. When the influence of 8% dietary fiber from WB on the development of colon tumors was compared with that of PS (WB:PS = 0:100), no significant difference was observed. However, combinations of WB and PS showed a greater protective effect than either WB or PS alone, at comparable levels of dietary fiber. The 50:50 combination of WB and PS showed maximum protection, while 25:75 and 75:25 combinations both produced intermediate effects. None of the diets showed any significant effect on the normal growth of rats. The results indicate that WB and PS fiber alone, and to a greater degree in combination, can offer protection against colon cancer promoted by high fat, low calcium diets. Diets that include wheat bran in combination with psyllium could be an effective means of reducing colon cancer risk in human populations addicted to high risk western diets.

Animals↗
PubMed1993

The diagnosis of CMV pneumonitis in lung and heart/lung transplant patients by PCR compared with traditional laboratory criteria.

Polymerase chain reaction (PCR) amplification of CMV DNA recovered from bronchial alveolar lavage (BAL) and peripheral blood samples was compared with tissue culture, cytology, and/or histology for the earlier detection of CMV pneumonitis in 12 recipients of single-lung or heart/lung transplants. In patients with confirmed CMV pneumonitis, cytological evidence of CMV disease in BAL samples was detected 38 +/- 14 days posttransplantation, while tissue culture and PCR-positive results were noted as early as 30 +/- 4.0 days and 18 +/- 4.6 days, respectively. While PCR was positive earlier than culture in a number of cases, culture-positive results were subsequently obtained in each case, consistent with earlier detection of viral replication by PCR as opposed to detection of latent virus. CMV was detected by PCR in 6 of 24 blood samples from patients with confirmed or suspected CMV pneumonitis, while results of all 24 blood samples were negative when assayed by tissue culture. PCR-based testing was more sensitive than traditional tests, allowing detection of viral replication earlier than tissue culture in the posttransplant period. PCR could provide a powerful means of monitoring the immunocompromised patients in whom preemptive therapeutic intervention for CMV disease is desirable.

Biopsy↗
PubMed1992

Fiberoptic bronchoplasty. Description of a simple adjunct technique for the management of bronchial stenosis following lung transplantation.

Bronchostenosis is a well-recognized complication of pulmonary transplantation occurring at the site of the anastomosis and occasionally spreading distally from the original site of obstruction. The management of these airway complications has relied heavily on stent placement that usually involves the use of a rigid bronchoscope and is a relatively complicated procedure in the patient requiring mechanical ventilation. Another has been the use of laser therapy in selected patients. We report three cases of postoperative bronchostenosis managed with bronchoscopically directed balloon dilatation. This relatively simple procedure performed under local anesthesia using a fiberoptic bronchoscope and a modification of the Seldinger technique for balloon placement permitted accurate and atraumatic dilatation of significant posttransplant stenosis. This technique may have potential for emergency and/or palliative management of postoperative, posttraumatic, or malignant airway obstruction.

Adult↗
PubMed1991

Complications of immunosuppression associated with weekly low dose methotrexate.

Complications of immunosuppression are thought to be rare with the use of low dose pulse methotrexate (MTX) for nonneoplastic conditions. We describe 4 complications of immunosuppression observed in a group of 41 patients who had received MTX for at least 6 months, during a 2-year period. We report the first case of a reversible lymphoproliferative disorder similar to that reported with immunosuppressive therapy associated with organ transplantation. Two cases of disseminated herpes zoster and 1 case with Pneumocystis carinii pneumonia are described. As the indications for the use of low dose MTX broaden and older patients with other comorbid diseases are included, our experience suggests that complications of immunosuppression with prolonged use of MTX may be seen more commonly.

Aged↗
PubMed1990

Results of single-lung transplantation for bilateral pulmonary fibrosis. The Toronto Lung Transplant Group.

Between November 1983 and August 1989, we performed single-lung transplantation for end-stage pulmonary fibrosis in 20 patients. Nine patients (45 percent) who survived for more than one year form the basis of this report. Before surgery, the nine survivors had severe restrictive lung disease, with a mean (+/- SD) vital capacity (VC) of 43 +/- 9 percent, a forced expiratory volume in one second (FEV1) of 50 +/- 9 percent, and a single-breath diffusing capacity (DLCO) of 36 +/- 9 percent of predicted values. One year after transplantation, the patients' VC had reached 69 +/- 10 percent, FEV1 79 +/- 15 percent, and DLCO 62 +/- 16 percent of predicted values. Relative perfusion to the transplanted lung rose from 63 +/- 14 percent (three days after surgery) to 77 +/- 7 percent within three months and stayed constant or increased slightly thereafter. Before surgery, despite supplemental oxygen at flow rates varying from 1 to 9 liters per minute, none of the patients could exercise beyond stage 1/2 (2.7 km [1.7 miles] per hour, 5 percent grade) on a modified Bruce treadmill-exercise protocol. All eight patients tested one year or more after transplantation achieved at least stage 1 (2.7 km [1.7 miles] per hour, 10 percent grade), and usually a higher stage, without supplemental oxygen. Arterial oxygen tension returned to normal values in most patients (87 +/- 13 mm Hg), and supplemental oxygen, which all patients required before surgery, was no longer needed by any patient after transplantation. We conclude that in carefully selected patients with end-stage pulmonary fibrosis, single-lung transplantation is an effective treatment.

Adolescent↗
PubMed1990

Sequestration of N-acetyl-beta-D-glucosaminidase in somatic cells during experimental bovine mastitis induced by endotoxin, Staphylococcus aureus or Streptococcus agalactiae.

Experimental mastitis was induced in cows by intramammary infusion of endotoxin, Staphylococcus aureus or Streptococcus agalactiae. The inflammatory response was monitored by somatic cell counting and N-acetyl-beta-D-glucosaminidase (NAGase). NAGase activity was analysed in fresh milk samples in parallel with samples treated by a cycle of freezing and thawing combined with detergent treatment to release the cell-bound NAGase. Before the udder reacted by inflammation, the total NAGase activity consisted of free extracellular activity. Later on when the inflammation was established, much of the milk NAGase remained sequestered intracellularly. S agalactiae was linked with a high degree of cellular NAGase sequestration indicating a blockage of the lysosomal release function from the phagocytes. S aureus delayed the inflammatory response.

Acetylglucosaminidase↗
PubMed1988

Frequency of allergy to Alternaria and Cladosporium in a specialist clinic.

In the literature there is considerable variation in the frequency of allergy to the moulds Alternaria iridis and Cladosporium herbarum. In 1985 a 6-month frequency study was performed in a specialist clinic with a patient population similar to the average specialist and out-patient clinics in Denmark as regards sex, age, and diagnoses. Allergy was confirmed by use of a purified and standardized extract, and SPT, CPT and RAST were performed. Among the 292 first referrals nine had allergy to Alternaria, and two to Cladosporium, corresponding to a frequency of 3.1 (1.0-6.5)% and 0.7 (0.1-3.6)%, respectively, with 99% confidence limits. Most of the patients were multi-allergics suffering from rhinoconjunctivitis as well as asthma.

Alternaria↗
PubMed1986

Diclofenac versus lidocaine as injection therapy in myofascial pain.

Twenty-four patients with localized myofascial pain were treated with injections, 11 with 2 ml lidocaine 1% and 13 with 2 ml diclofenac (Voltaren) (50 mg) given in the trigger-point. The effect of therapy was measured by visual analogue scale (VAS) during 5 h corresponding to the expected pharmacological period of effect. Despite the small number of patients a clear trend was seen towards better treatment results with diclofenac, and after 4 h the difference between the two treatments was significant (p less than 0.05). Compared with the pain score value at the start the treatment with diclofenac gave a significant alleviation (p less than 0.05) after 3 h, whereas treatment with lidocaine did not give any significant change in pain level. The demonstrated effect of a prostaglandin synthesis inhibitor illustrates how inflammation is involved as an etiological factor in myofascial pain.

Diclofenac↗
PubMed1985

Fetal hydrocephalus: a case of ventricular-amniotic shunting.

The case we have reported describes the management of fetal hydrocephalus using an intrauterine ventricular-amniotic shunt, which unfortunately was not recovered after delivery. To prevent this potential complication, we suggest such shunts be made radiopaque. The encouraging results in this case are attributed to the efforts of an interdisciplinary team and suggest that vascular accidents may well prove to be amenable to treatment by this new procedure.

Adult↗
PubMed1980

Metabolism and effects of progesterone in the human endometrial adenocarcinoma cell line HEC-1.

Human endometrial adenocarcinoma cells (HEC-1 line) were incubated with 14C-progesterone. Four major labeled metabolites, 3 beta-hydroxy 5 alpha-pregnan-20-one, 5 alpha-pregnane-3 beta, 20 alpha-diol, 20 alpha-hydroxy-4-pregnen-3-one and 5 alpha-pregnane-3, 20-dione were separated by thin layer chromatography, further purified by high pressure liquid chromatography, and finally identified by addition of carriers and crystallization to constant specific activity. Among these metabolites, 5 alpha-pregnane-3 beta, 20 alpha-diol seems characteristic of this cell line since its formation from labeled progesterone was not detected in normal endometrium or in 2 specimens of endometrial adenocarcinoma. The growth of HEC cells was unaffected by either progesterone or medroxyprogesterone acetate, a slowly metabolized progestin, at about 10(-6) M levels but was inhibited by about 10(-5) M concentrations of these compounds.

Adenocarcinoma↗