A clinical study of hypoxia and metallothionein protein expression in squamous cell carcinomas.

The objective was to discover whether the oxygen-regulated protein, metallothionein, is expressed in the hypoxic cells of squamous cell carcinomas. Twenty patients with squamous cell carcinoma of the uterine cervix or head and neck were infused with a solution of the hypoxia marker, pimonidazole hydrochloride, at a dose of 0.5 g/m2. The following day, biopsies were collected, formalin fixed, paraffin embedded, and sectioned at 4 microm. Sections from each biopsy were immunostained for pimonidazole binding, metallothioneins I and II, involucrin, and proliferating cell nuclear antigen. A total of 84 biopsies were analyzed. Sixty-four of 84 biopsy sections contained hypoxia. Of the hypoxia-containing sections, 43 of 64 or 67% showed no microregional overlap between hypoxia and metallothionein; 7 of 64 showed overlap; and 14 of 64 showed a combination of overlap and no overlap. On a tumor-by-tumor basis, 5 of 7 head and neck and 7 of 13 cervix tumors showed no overlap between metallothionein and hypoxia at the microregional level. Ranges for the percentage of the area of hypoxia in head and neck (<0.9 to 17%) and cervix (<0.1 to 14%) tumors were similar. In the hypoxia-containing sections, immunostaining for involucrin, a molecular marker for differentiation, overlapped with that for hypoxia in 82% of the cases. The majority of hypoxic cells in squamous cell carcinomas do not express metallothionein protein, although metallothionein is induced by hypoxia in human tumor cells in vitro. Hypoxic cells in human tumors tend to be in regions immunostaining for involucrin, and it seems possible that differentiation of hypoxic cells in squamous cell carcinomas might affect metallothionein I and II expression.

Hypoxia and vascular endothelial growth factor expression in human squamous cell carcinomas using pimonidazole as a hypoxia marker.

Hypoxia in human tumors is associated with poor prognosis, but the molecular mechanisms underlying this association are poorly understood. One possibility is that hypoxia is linked to malignant progression through vascular endothelial growth factor (VEGF) induction and the associated angiogenesis and metastasis. The present clinical study measures hypoxia and VEGF expression on a cell-by-cell basis in human squamous cell carcinomas to test the hypothesis that hypoxia and VEGF protein expression are coupled in human tumors. Eighteen patients with invasive squamous cell carcinoma of the uterine cervix and head and neck have been investigated by a quantitative image analysis of immunostained sections from their tumors. The hypoxia marker pimonidazole was used to measure tumor hypoxia, and a commercially available antibody was used to measure VEGF protein expression. A quantitative immunohistochemical comparison of hypoxia and VEGF protein expression revealed no correlation between the two factors.

Platelet 5-hydroxytryptamine (5-HT) transporter and 5-HT2A receptor binding after chronic hypercorticosteronemia, (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane administration or neurotoxin-induced depletion of central nervous system 5-HT in the rat.

There is considerable evidence that the number of platelet 5-hydroxytryptamine (5-HT) transporter binding sites, as measured by [3H]imipramine binding, are significantly decreased, and platelet 5-HT2 receptor density is increased, in drug-free patients with major depression. To investigate whether these changes in the platelet 5-HT transporter or 5-HT2 receptor sites resulted from known or hypothesized biochemical changes observed in major depression, we examined, in the rat, whether a chronic hyperglucocorticoid state, or decreases or increases in central nervous system 5-HT neurotransmission, altered binding of the selective ligands [3H]citalopram and [125I] (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane to platelet and brain 5-HT transporters and 5-HT2 receptors, respectively. Chronic (6 weeks) hypercorticosteronemia did not alter either brain or platelet 5-HT transporter or 5-HT2A receptor binding. Similarly, 8-week administration of the 5-HT2A/5-HT2C agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane, at a dose which down-regulates brain 5-HT2A/2C receptors, did not alter brain or platelet 5-HT transporters or platelet 5-HT2A receptors. Additionally, para-chloroamphetamine-(11 weeks) or fenfluramine-induced chronic (1.5-10 weeks) depletion of central nervous system 5-HT did not alter platelet 5-HT transporter or 5-HT2A receptor binding. Finally, there was no correlation between the number of 5-HT transporters in brain and platelets in any of the control or treatment groups. These findings suggest that the observed changes in platelet 5-HT transporter and 5-HT2A receptor binding in depressed patients are more apt to be of genetic origin (i.e., trait-dependent) rather than an epiphenomenon of hypercortisolemia or altered central nervous system 5-HT status.

Non-disjunction in human sperm: results of fluorescence in situ hybridization studies using two and three probes.

Fluorescence in situ hybridization using two or three probes was utilized to estimate the incidence of diploidy, the incidence of disomy for the sex chromosomes and chromosomes 16 and 18, and the proportion of Y- and X-chromosome bearing sperm, in a series of normal males. Our results demonstrate the importance of using an approach capable of distinguishing disomy from diploidy, as most donors had levels of diploidy higher than the disomy levels of individual chromosomes. Our analyses suggest the existence of chromosome-specific mechanisms of paternal non-disjunction, as sex chromosome disomy was approximately 1.5 times as common as disomy 16, and over two times as common as disomy 18. In studies of gametic sex ratio, we found little evidence for marked deviation from an expected 1:1 ratio.

Effects of repetitive motion on human fibroblasts.

Repetitive motion injuries such as tendonitis are common sports injuries. However, few scientific studies are available on the effects of repetitive motion on mesenchymal cells and the presumed inflammatory response. This study used a new in vitro model to study the effects of repetitive motion. Human tendon fibroblasts were subcultured and plated on culture wells with flexible bottoms. The cells were repetitively stretched using a micro-processor-controlled pressure unit that causes a cyclic deformation of the flexible bottom. The wells were divided in the following groups: group I controls without repetitive motion, group IIA repetitive motion with 0.25 strain at 0.17 Hz (10 cycles.min-1), group IIB repetitive motion with 0.25 strain and 0.17 Hz in presence of 25 microM indomethacin, and group III repetitive motion with 0.25 strain at 1 Hz (60 cycles.min-1). After 3 h of stimulation the supernatant fluids were harvested and evaluated for prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and lactate dehydrogenase (LDH). The results showed significantly (P < 0.001) increased levels of PGE2 in groups IIA (46.9 +/- 4.7 pg.0.1 ml-1) and III (65.7 +/- 8.0 pg.0.1 ml-1). This represents a 1.3- and 1.8-fold increase, respectively, compared with the control group I (36.4 +/- 5.9 pg.0.1 ml-1). LTB4 was significantly (P < 0.001) elevated in the indomethacin-treated group IIB (45.0 +/- 11.0 pg.0.1 ml-1) compared with very low levels in all other groups. LDH was not significantly different in any of the experimental groups compared with the control group I. The results indicate that repetitive motion induces production of PGE2.(ABSTRACT TRUNCATED AT 250 WORDS)