Dietary phytoestrogens and their role in hormonally dependent disease

Epidemiological studies suggest that diets rich in phytoestrogens (plant estrogens), particularly soy and unrefined grain products, may be associated with low risk of breast and prostate cancer. It has also been proposed that dietary phytoestrogens could play a role in the prevention of other estrogen-related conditions, namely cardiovascular disease, menopausal symptoms and post-menopausal osteoporosis. However, there is no direct evidence for the beneficial effects of phytoestrogens in humans. All information is based on consumption of phytoestrogen-rich diets, and the causal relationship and the mechanisms of phytoestrogen action in humans still remain to be demonstrated. In addition, the possible adverse effects of phytoestrogens have not been evaluated. It is plausible that phytoestrogens, as any exogenous hormonally active agent, might also cause adverse effects in the endocrine system, i.e. act as endocrine disrupters.

Genistein exerts estrogen-like effects in male mouse reproductive tract

The aim of this study was to evaluate the estrogenicity of genistein in the neonatal and adult male mouse reproductive tract. In intact adults, genistein (2.5 mg s.c./kg of body weight/day for 9 days) reduced testicular and serum testosterone concentrations, pituitary LH-content and prostate weight. In castrated adults, genistein (0.025-2.5 mg s.c./kg of body weight) increased expression of c-fos gene in prostatic urethra. In adult, neonatally estrogenized mice showing an increased estrogen sensitivity, a 10-day treatment with genistein (2.5 mg s.c./kg of body weight) induced development of squamous epithelial metaplasia in prostatic collecting ducts. Neonatally, only a very high dose of genistein (1 mg/pup per day; i.e. approximately 500 mg/kg of body weight) induced persistent structural changes, similar to those seen in mice treated neonatally with diethylstilbestrol, in the urethroprostatic complex. These results suggest that in adult males, genistein induces the typical estrogenic effects in doses comparable to those present in soy-based diets, while in neonatal animals, considerably higher doses are required to show estrogen-like activity.

Effect of long-term salmeterol treatment on exercise-induced asthma

BACKGROUND

With long-term administration of salmeterol, the extent of protection afforded by the drug against experimental precipitants of asthma such as methacholine and adenosine may decrease. Whether this effect extends to a clinically relevant stimulus such as exercise is unknown.

METHODS

We performed a random-order, double-blind, crossover trial in 20 patients with exercise-induced asthma. Each patient received inhaled salmeterol or placebo twice daily for a month, with a one-week washout period between treatments. The patients performed cycle ergometry while breathing frigid air 30 minutes after the morning dose and 9 hours later on the 1st, 14th, and 29th study days. The primary end point was the extent of the decrease in forced expiratory volume in 1 second (FEV1) 10 minutes after exertion.

RESULTS

With placebo, significant airway narrowing developed at all times (mean [+/-SE] decrease from base line in FEV1, 19+/-2 percent in the morning and 18+/-2 percent in the evening). The morning dose of salmeterol attenuated the degree of bronchoconstriction at all times (decrease in FEV1 on day 1, 5+/-2 percent; on day 14, 10+/-3 percent; and on day 29, 9+/-3 percent; P=0.10). Its ability to act throughout the day, however, decreased with long-term administration (decrease in FEV1 from morning to evening on day 1, 6+/-2 percent; on day 14, 15+/-3 percent; and on day 29, 14+/-3 percent; P=0.003).

CONCLUSIONS

Protection against exercise-induced asthma is maintained with long-term administration of salmeterol, but the length of time that the drug remains active after a single dose decreases.

Comparison of two dosage regimens of albuterol in acute asthma

BACKGROUND

The standard therapy for acute episodes of asthma in the United States consists of three 2.5-mg doses of aerosolized albuterol given every 20 minutes. Whether this approach represents optimum therapy has never been tested.

METHODS

This study employed a prospective, sequential design in which the effects of two doses of 5.0 mg of aerosolized albuterol administered during 40 minutes (high dose) were contrasted with the standard dose (three 2.5-mg doses). Improvements in pulmonary function, clinical resolution of the asthma attacks, and admission rates were used as primary endpoints. Both regimens were part of an overall care plan that involved objective, pretested decision algorithms.

RESULTS

In an emergency department, 160 patients who presented with acute exacerbations of asthma received either standard (n = 80) or high-dose (n = 80) albuterol treatment. There were no significant baseline differences in gender, racial composition, clinical signs and symptoms, medication use, or peak expiratory flow (PEF) between the groups. Both treatment schedules were effective, but the high-dose regimen increased lung function more rapidly and to a greater extent than standard-dose therapy. It also resulted in lower charges to third party payers. More subjects attained the discharge criteria quicker and left the emergency department with peak expiratory flows closer to normal. Fewer patients in the high-dose group were admitted, but this trend did not quite reach statistical significance.

CONCLUSIONS

Two 5.0-mg treatments of aerosolized albuterol at a 40-minute interval provide effective therapy for acute exacerbations of asthma. This combination of dose and frequency promotes maximum bronchodilatation, increases efficiency, and reduces the risks of undertreatment.

Inhibition of 17beta-hydroxysteroid oxidoreductase by flavonoids in breast and prostate cancer cells

Several flavonoids and isoflavonoids were found to inhibit 17beta-oxidoreduction of estrogens by the purified 17beta-HSOR type 1, or in cell lines expressing 17beta-HSOR type 1 enzyme (T-47D breast cancer cells) or type 2 (PC-3 prostate cancer cells). The structural demands for the inhibition of estrone (E1) reduction and estradiol (E2) oxidation catalyzed by 17beta-HSOR types 1 and 2, respectively, were not identical. Flavones, flavanones, and isoflavones hydroxylated at both the double ring (positions 5 and 7) and ring B (position 4') were the most potent inhibitors of E1 reduction in T-47D cells, and by the purified type 1 enzyme whereas flavones hydroxylated at positions 3, 5, and 7 of rings A and C, with or without a hydroxyl group in ring B, were capable of inhibiting E2 oxidation in PC-3 cells. Change to flavanone structure, or hydroxylation at position 3 of ring C of flavones, or methylation of the hydroxyl group at position 4' of ring B of flavones and isoflavones reduced or abolished their inhibitory activity on E1 reduction in T-47D cells. On the contrary, hydroxyl group at position 3 of flavones (flavonol structure) markedly increased the inhibition of E2 oxidation in PC-3 cells. Thus, changes in the number and location of hydroxyl groups may discriminate inhibition of E1 reduction and E2 oxidation. Some of the differences may be due to differences in pharmacokinetics of these compounds in T-47D and PC-3 cells. Inhibition of 17beta-HSORs could lead to an alteration in the availability of the highly active endogenous estrogen, but the effects of these compounds in vivo cannot be predicted on the basis of these results alone. Some of these compounds (isoflavones) are estrogenic per se, and they may replace endogenous estrogens, whereas flavones are only very weakly estrogenic or nonestrogenic. Regarding prevention or treatment of estrogen-related diseases, apigenin, coumestrol, and genistein raise special interest.

Phytoestrogens: potential endocrine disruptors in males

Exposure to diethylstilbestrol (DES) induces persistent structural and functional alterations in the developing reproductive tract of males. It is possible that xenoestrogens other than DES alter sexual differentiation in males and account for the increasing incidence of developmental disorders of the reproductive tract in men and wild animals. Phytoestrogens (coumestans, isoflavonoids, flavonoids, and lignans) present in numerous edible plants are quantitatively the most important environmental estrogens when their hormonal potency is assessed in vitro. They exert their estrogenic activity by interacting with estrogen receptors (ERs) in vitro. They may also act as antiestrogens by competing for the binding sites of estrogen receptors or the active site of the estrogen biosynthesizing and metabolizing enzymes, such as aromatase and estrogen-specific 17 beta-hydroxysteroid oxidoreductase (type 1). In theory, phytoestrogens and structurally related compounds could harm the reproductive health of males also by acting as antiestrogens. There are very little data on effects of phytoestrogens in males. Estrogenic effects in wildlife have been described but the evidence for the role of phytoestrogens is indirect and seen under conditions of excessive exposure. In doses comparable to the daily intake from soybased feed, isoflavonoids such as genistein were estrogen agonists in the prostate of adult laboratory rodents. When given neonatally, no persistent effects were observed. In contrast, the central nervous system (CNS)-gonadal axis and the male sexual behavior of the rat appear to be sensitive to phytoestrogens during development. The changes were similar but not identical to those seen after neonatal treatment with DES, but higher doses of phytoestrogens were needed.

Observations on the effects of aerosolized albuterol in acute asthma

To determine the dose of albuterol required to terminate acute episodes of asthma, 92 acutely ill subjects received three doses of 2.5 mg each by nebulization every 20 min. Peak expiratory flow rates (PEFR) and signs and symptoms were serially monitored. A dose-response increase in pulmonary function was found, but only 66% of the subjects improved sufficiently to be sent home. Of these, 56% required < or = 5.0 mg of drug to reach the discharge threshold, whereas the remainder needed 7.5 mg. In 34% of participants, albuterol was ineffectual. These individuals were characterized by more severe obstruction at presentation, and after three doses of medication their PEFR still did not exceed 40% of the expected value. Further treatment in the emergency department (ED) or hospital was not immediately helpful, and these patients ultimately required 3.8 +/- 0.4 d of inpatient care to become asymptomatic. There were no discernible differences between responders and nonresponders in the type or quantity of medications used. However, the nonresponders had more severe disease as measured by recurrent hospitalizations and ED visits. This study demonstrates that, in emergency situations, albuterol does not relieve acute airway obstruction in all asthmatic individuals with equal efficacy. Two-thirds of patients are sensitive, and in these patients 5 to 7.5 mg of albuterol provides optimal treatment. In the remainder, albuterol, even in high doses, has little effect for days.

The influence of parasympatholytics on the resolution of acute attacks of asthma

PURPOSE

To evaluate the role of parasympatholytics in the resolution of acute attacks of asthma.

METHODS

This study employed a prospective sequential design in which the influence of 0.5 and 1.0 mg of ipratropium bromide on peak expiratory flow rates (PEFR), hospital admissions, and length of stay (LOS) in the emergency department (ED) was evaluated. The parasympatholytic was added to a well-investigated standard therapeutic regimen that was anchored by the use of repetitive doses of albuterol, and employed pretested decision algorithms.

RESULTS

One hundred and thirty-one patients received ipratropium (l) and 123 who did not (NI) served as controls. There were no significant pretreatment between group differences in gender, racial composition clinical signs and symptoms, or PEFR. The presence of ipratropium in the regimen did not influence discharge/admission patterns, LOS, the rate of improvement of the patients, or the level of PEFR achieved.

CONCLUSION

Anticholinergic agents such as ipratropium are not first-line treatments for acute asthma. They do not add any therapeutic benefit to the effects of albuterol given in divided doses over 1 hour, nor do they facilitate recovery in patients whose immediate response to sympathomimetics is impaired.

Hyperfractionated craniospinal radiation in medulloblastoma

From 1986 to 1991, 13 patients at Northwestern Memorial Hospital were entered onto a pilot study designed to test the feasibility of treating children with medulloblastoma (11 patients) or primitive neuroectodermal tumors of the cerebral hemispheres (2 patients) with hyperfractionated craniospinal radiotherapy (HFxRT). Follow-up times ranged from 10 to 96 months with a median of 53 months. The patients were prospectively divided among three treatment arms depending on prior treatment history, if any, and degree of surgical resection. The 3 patients in group I had undergone gross total resection of the primary site, receiving 64.8 Gy to the primary site and 31.2 Gy directed to the craniospinal axis (CSA). Of these 3 patients, patient 1 had residual disease in the thoracic spine at T-10. The 8 patients in group II, who had gross residual disease remaining at the primary site, received 72 Gy to the primary site and 34 Gy to the CSA. Five of these eight patients in group II also received 8-in-1 chemotherapy. The 2 patients in group III had already failed chemotherapy and were then treated with 60 Gy to the primary site and 26 Gy to the CSA. Of the 11 patients in groups I and II, 7 of the 11 (64%) have never recurred. Two of the three group-I patients have not recurred, and 5 of the 7 group-II patients have not recurred. In addition, patient 7 (group II) remains alive after salvage with bone marrow transplant, following a local failure bordering the tentorium. Unfortunately, neither of the group-III patients could be salvaged with HFxRT. Acute/subacute toxicities included 7 cases of external auditory canal or skin desquamation, 2 cases of postradiation somnolence, and 1 case each of poor wound healing and neutropenia. Chronic toxicities included hypothyroidism in 2 patients and growth problems in 2 patients. Neuropsychologic complications affected only the 3 youngest patients in the study. Three patients developed neurologic sequelae attributed to radiation, including 1 with progressive urinary incontinence, 1 who developed a transient ischemic attack, and 1 who became progressively ataxic. Our research, although based on a small number of patients, suggests that hyperfractionated radiation therapy to craniospinal access is feasible and that the survival results are favorable. This treatment strategy should be further explored in a phase-III randomized trial.

Optic pathway tumors in children: the effect of neurofibromatosis type 1 on clinical manifestations and natural history

OBJECTIVE

To distinguish the clinical manifestations and natural history of optic pathway tumors (OPT) associated with neurofibromatosis type 1 (NF-1 OPT) from that of OPT not associated with NF-1 (non-NF-1 OPT).

METHODS

Two groups of children with OPT were compared: (1) 17 children with NF-1 OPT who were followed prospectively, and (2) 19 children with non-NF-1 OPT who were identified retrospectively by a review of medical records.

RESULTS

Precocious puberty was a common initial sign in the children with NF-1 OPT (5/17), and was not found in any patients without NF-1. In contrast, children with non-NF-1 OPT had symptoms attributable to increased intracranial pressure (12/19 and nystagmus (5/19); these symptoms were not found in any patient with NF-1. Decreased visual acuity at the time of diagnosis was common in both groups. There was no significant difference between the children with NF-1 OPT and those with non-NF-1 OPT as to age at diagnosis or sex distribution. Optic nerve involvement was more common in NF-1 (p < 0.001). Both isolated and bilateral optic nerve tumors were found exclusively in children with NF-1, whereas chiasmal (p = 0.016) and optic tract involvement (p = 0.001) were more common in those with non-NF-1 OPT. Radiographic evidence of hydrocephalus was found in none of the children with NF-1 OPT compared with 79% of the non-NF-1 OPT group. Progressive disease was seen in 12% of patients with NF-1 OPT compared with 63% of those with non-NF-1 OPT.

CONCLUSIONS

Differences exist between NF-1 OPT and non-NF-1 OPT both at the time of diagnosis and during follow-up. Optic pathway tumors caused by NF-1 and non-NF-1 OPT have different biologic properties that distinguish both their initial clinical manifestations and their natural history.

A pilot study of isotretinoin in the treatment of juvenile chronic myelogenous leukemia

BACKGROUND

Juvenile chronic myelogenous leukemia (CML) is a rare myeloproliferative disease of infants and young children for which there is no effective therapy other than allogeneic bone marrow transplantation. In vitro, isotretinoin (13-cis-retinoic acid) attenuates both the spontaneous proliferation of leukemic peripheral-blood progenitor cells (granulocyte-macrophage colony-forming units) and their selective hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). We conducted a pilot study to evaluate the clinical efficacy of isotretinoin in juvenile CML.

METHODS

To be eligible the patients had to have newly diagnosed untreated disease, leukocytosis with monocytosis, marrow with less than 25 percent blasts, hepatosplenomegaly, no chromosomal abnormalities, and negative viral cultures and antibody titers. Isotretinoin was administered orally in single daily doses of 100 mg per square meter of body-surface area. When possible, patients subsequently underwent bone marrow transplantation.

RESULTS

Ten children (median age, 10 months) were enrolled in the study. In all 10 there was spontaneous colony formation of leukemic progenitor cells in vitro. In the eight patients tested there was hypersensitivity to GM-CSF. The only toxic effect of isotretinoin therapy was cheilitis in two patients. Four children had disease progression. Two children had complete responses to isotretinoin (normalization of the white-cell count and disappearance of organomegaly), three had partial responses (more than a 50 percent reduction in the white-cell count and degree of organomegaly), and one had a minimal response (more than a 50 percent reduction in the white-cell count, but a 26 to 50 percent reduction in the degree of organomegaly). The median duration of response was 37 months (range, 6 to 83). Three of the four children who had a complete or partial response and who did not undergo bone marrow transplantation were alive 36 to 83 months after the diagnosis of juvenile CML. The spontaneous colony formation in vitro was reduced in samples from the five patients in whom this factor was reassessed during treatment. There was also a reduction in the hypersensitivity of leukemic progenitor cells to GM-CSF in the two patients retested.

CONCLUSIONS

Isotretinoin can induce durable clinical and laboratory responses in patients with juvenile CML.

Osteoblastic metastases from astrocytomas: a report of two cases

The spread of primary central nervous system (CNS) neoplasms beyond the confines of the neuraxis is a relatively uncommon observation. Extraneural metastases involving bone are quite rare, and have been observed almost exclusively in cases of medulloblastoma, high-grade (III-IV) astrocytoma, and glioblastoma multiforme. To date there has been only one case reported of bone metastasis from a "well-differentiated" astrocytoma. We now report two cases of astrocytoma in children with diffuse osteoblastic metastases and a fulminant clinical course. These cases demonstrate that due to the potential morphologic heterogeneity of these neoplasms, an initial biopsy diagnosis of low-grade astrocytoma does not always imply a benign clinical course.

Use of lectins in the study of histogenesis of renal cysts

Two peroxidase-labeled lectins, from Tetragonolobus lotus and from peanut (Arachis hypogaea), were used in the study of five cases of polycystic kidney of different types. The two lectins bind with high selectivity of proximal tubules and collecting ducts, respectively. It was found that in infantile polycystic kidneys the cyst walls consistently stained with peanut lectin but not with Tetragonolobus lectin, confirming their origin from collecting ducts only. In adult polycystic kidneys there was mixture of two types of cysts: one positive for peanut, the other positive for Tetragonolobus. The two lectins were, however, mutually exclusive. Moreover, some cysts did not stain for either lectin. The findings suggest that in this type of disease a cyst can originate from any portion of the nephron. The data are also consistent with reports in the literature which used microdissection techniques or chemical analysis of the cyst content. The use of lectins will probably be useful in investigating other types of cystic kidneys, such as dysplastic kidneys and experimental models. The technique is relatively easy to use, but must be applied under strictly controlled conditions, especially when using surgical or postmortem material.

Hallucinogenic amphetamine selectively destroys brain serotonin nerve terminals

(+/-)-3,4-Methylenedioxyamphetamine (MDA), an amphetamine analog with hallucinogenic activity, produced selective long-lasting reductions in the level of serotonin, the number of serotonin uptake sites, and the concentration of 5-hydroxyindoleacetic acid in rat brain. Morphological studies suggested that these neurochemical deficits were due to serotonin nerve terminal degeneration. These results show that MDA has toxic activity for serotonin neurons in rats and raise the question of whether exposure to MDA and related hallucinogenic amphetamines can produce serotonin neurotoxicity in the human brain.

Attenuation changes of the normal and ischemic canine kidney. Dynamic CT scanning after intravenous contrast medium bolus

The potential of CT scanning to explore total and regional renal blood flow was evaluated in a dog model with unilateral renal artery stenosis (n = 7, reduction of renal blood flow: 32-75% of base line flow). Attenuation versus time curves were generated for the renal cortex and medulla, as well as for the aorta and renal vein. A fast CT scanner was used which allowed for up to 24 scans/minute at the same level (slice thickness: 10 mm). A total of 10 ml contrast medium was injected into a peripheral vein for each scan series taken. During baseline conditions, the curve of the renal cortex and medulla demonstrated 2 peaks. The first peak was mainly related to early vascular enhancement, whereas the second peak corresponded mainly to the appearance of contrast medium in the distal convolutes and collecting ducts. Ischemia of the kidney resulted in a reduction of the first peak and a flattening of the leading edge slope. Transport of contrast medium through the extravascular compartments of the kidney was delayed during ischemia. Relative renal blood flow was obtained from the CT data by dividing peak enhancement by rise-time as assessed from the cortical curve. All measurements were related to baseline flow and validated by flow measurements using radioactive labeled microspheres (n = 5). Correlation was found to be r = 0.97.

[1 year's experience with a 57-cm image intensifier in a universal roentgen work station]

3342 patients were examined by means of a 57 cm image intensifier during one year. The installation permits examination with the patient standing or lying. The resolution was measured with a lead grid under conditions resembling actual practice and were found to be similar to those obtained with angiographic equipment. Using a medium format technique for examining the gut and vascular system resulted in radiographic quality which was not significantly different from the use of a large format technique. For examination of the skeleton, radiographic quality, using the intensifier, was markedly poorer than that resulting from Bucky examinations. There was no diagnostic difference when carrying out lymphograms. The large intensifier window of 53 cm was particularly advantageous for DSA of the pelvic and lower limb vessels when compared with smaller intensifiers. Possible savings of film and contrast medium costs are discussed.

Tumor infiltration of the bone marrow: comparative study using computed tomography

During the past two years five patients with malignant primary bone tumors undergoing amputation or resection of the involved bone had preoperative computed tomography (CT) examination of the medullary cavity. The contralateral extremity was used as a control in all cases. The positive attenuation coefficient of the marrow indicated the extent of tumor infiltration. The correlation between the preoperative CT and pathologic measurement ranged between 1-8 mm, an accuracy greater than 94%.

Benign glandular inclusions in lymph nodes, endosalpingiosis, and salpingitis isthmica nodosa in a young girl with clear cell adenocarcinoma of the cervix

A 12-year-old girl underwent radical surgery for clear cell adenocarcinoma of the endocervix. Bilaterally dilated fallopian tubes with hyperplastic mucosal folds and salpingitis isthmica nodosa were found in association with benign glandular inclusions in a para-aortic lymph node and in the serosa of pelvic organs. Changes in the müllerian-derived epithelium appear to be a common denominator of these unusual lesions in this young girl. A primary growth disturbance of the cells of the müllerian system, which was conditioned during embryonic development and manifested itself later in life in response to appropriate stimuli associated with menarche, is postulated as the underlying abnormality.

The human fetal heart in the second trimester of gestation: a gross morphometric study of normal fetuses

One hundred fifty-three midtrimester fetuses obtained from normal pregnancies terminated for nonmedical reasons were studied to establish normal standard measurements. Mean, standard deviation, range, and percentiles of body weight, foot length, crown-rump length, biparietal diameter, cardiac weight, thickness of ventricles, and ventricular septum were derived by computer analysis. Statistical analysis showed no sex difference. Equations for predicting body weight, cardiac weight, and septal thickness were derived with the use of fetal age and biparietal diameter as variables. The mean ratio of septal to left ventricular wall thickness was 1.14 +/- 0.34; a ratio of 1.3 or greater was found in 25% and a ratio of 1.5 or greater in 10% of this cohort. The results are at variance with the reported high incidence of septal hypertrophy seen in normal developing fetal hearts. We suggest that septal hypertrophy, ratio of 1.5 or greater, may reflect disturbances in fetal or placental circulation and warrants careful monitoring of the pregnancy.

Single-photon emission computed tomography (SPECT) for assessment of hepatic lesions

Single-photon emission computed tomography (SPECT) and conventional scintigraphy were compared in 130 patients examined to assess hepatic involvement in malignant disease. Transmission computed tomography (TCT) served as the reference method against which SPECT and conventional scintigraphy were compared. The sensitivity of SPECT was calculated for lesions grouped according to diameter as well as location. The Bayesian theorem was used to assess the reliability of both SPECT and conventional scintigraphy. SPECT identified only 52% of lesions with a diameter of 1.5-2.0 cm. It was also shown that the sensitivity of SPECT was lowest for small lesions in the middle third of the liver. A comparison of the final diagnosis demonstrated that SPECT had greater sensitivity, specificity, and accuracy than conventional scans, and is superior at low disease prevalence. At high disease prevalence, SPECT has a lower rate of false negatives. SPECT appears to be the superior imaging modality for evaluation of the liver in malignant disease.

Renovascular hypertension associated with a pelvic kidney and multicystic dysplasia

We report on a 9-year-old boy with severe hypertension due to a variant of fibromuscular dysplasia of the renal artery supplying a functioning pelvic kidney. The other kidney proved to be a nonfunctioning multicystic remnant and several other congenital abnormalities of the genitourinary tract were present. Corrective vascular surgery was followed by normalization of arterial pressure and significant reduction of plasma renin activity. This is the first case report of renovascular hypertension due to renal artery stenosis in a single functioning pelvic kidney.