An achaete-scute homologue essential for neuroendocrine differentiation in the lung

In Drosophila and in vertebrates, the achaete-scute family of basic helix-loop-helix transcription factors plays a critical developmental role in neuronal commitment and differentiation. Relatively little is known, however, about the transcriptional control of neural features in cells outside a neuronal context. A minority of normal bronchial epithelial cells and many lung cancers, especially small-cell lung cancer, exhibit a neuroendocrine phenotype that may reflect a common precursor cell population. We show here that human achaete-scute homologue-1 (hASH1) is selectively expressed in normal fetal pulmonary neuroendocrine cells, as well as in the diverse range of lung cancers with neuroendocrine features. Strikingly, newborn mice bearing a disruption of the ASH1 gene have no detectable pulmonary neuroendocrine cells. Depletion of this transcription factor from lung cancer cells by antisense oligonucleotides results in a significant decrease in the expression of neuroendrocrine markers. Thus, a homologue of Drosophila neural fate determination genes seems to be necessary for progression of lung epithelial cells through a neuroendocrine differentiation pathway that is a feature of small-cell lung cancer, the most lethal form of human lung cancer.

Identification of a human achaete-scute homolog highly expressed in neuroendocrine tumors

Basic helix-loop-helix transcription factors of the achaete-scute family are instrumental in Drosophila neurosensory development and are candidate regulators of development in the mammalian central nervous system and neural crest. We report the isolation and initial characterization of a human achaete-scute homolog that is highly expressed in two neuroendocrine cancers, medullary thyroid cancer (MTC) and small cell lung cancer (SCLC). The human gene, which we have termed human achaete-scute homology 1 (hASH1), was cloned from a human MTC cDNA library. It encodes a predicted protein of 238 aa that is 95% homologous to mammalian achaete-scute homolog (MASH) 1, a rodent basic helix-loop-helix factor. The 57-residue basic helix-loop-helix domain is identical to that in the rodent gene, and the basic and helical regions, excluding the loop, are 72-80% identical to Drosophila achaete-scute family members. The proximal coding region of the hASH1 cDNA contains a striking 14-copy repeat of the triplet CAG that exhibits polymorphism in human genomic DNA. Thus, hASH1 is a candidate locus for disease-causing mutations via triplet repeat amplification. Analysis of rodent-human somatic cell hybrids permitted assignment of hASH1 to human chromosome 12. Northern blots revealed hASH1 transcripts in RNA from a human MTC cell line, two fresh MTC tumors, fetal brain, and three lines of human SCLC. In contrast, cultured lines of non-SCLC lung cancers and a panel of normal adult human tissues showed no detectable hASH1 transcripts. Expression of hASH1 may provide a useful marker for cancers with neuroendocrine features and may contribute to the differentiation and growth regulation of these cells.

PGP9.5 as a candidate tumor marker for non-small-cell lung cancer

PGP9.5 is a neurospecific peptide that functions to remove ubiquitin from ubiquitinated proteins and prevents them from targeted degradation by proteasomes. Using the serial analysis of gene expression method (SAGE), we observed that the PGP9.5 transcript was highly expressed in primary lung cancers and lung cancer cell lines but was not detectable in the normal lung. Here we examined the expression of PGP9.5 protein in normal lung epithelium, lung tumor cell lines, and 98 resected primary non-small-cell lung carcinomas (NSCLCs). We found PGP9.5 reactivity in normal lung in a pattern compatible with K-cells of the diffuse neuroendocrine system. However, the PGP9.5 was present in both small-cell lung cancer (SCLC) and NSCLC cell lines (22/24) independent of neuronal differentiation. In primary NSCLCs, 54% (53/98) of the cases had positive PGP9.5 staining, and the expression of protein was strongly associated with pathological stage of the cancer. It was present in 44% (29/66) of stage I NSCLCs and in 75% (24/32) of stage II and IIIA NSCLCs (p = 0.0032). These results suggest that the increased expression of PGP9.5 is specifically associated with lung cancer development and may serve as a potential marker for the detection of lung cancer.

RREB-1, a novel zinc finger protein, is involved in the differentiation response to Ras in human medullary thyroid carcinomas

An activated ras oncogene induces a program of differentiation in the human medullary thyroid cancer cell line TT. This differentiation process is accompanied by a marked increase in the transcription of the human calcitonin (CT) gene. We have localized a unique Ras-responsive transcriptional element (RRE) in the CT gene promoter. DNase I protection indicates two domains of protein-DNA interaction, and each domain separately can confer Ras-mediated transcriptional inducibility. This bipartite RRE was also found to be Raf responsive. By affinity screening, we have cloned a cDNA coding for a zinc finger transcription factor (RREB-1) that binds to the distal RRE. The consensus binding site for this factor is CCCCAAACCACCCC. RREB-1 is expressed ubiquitously in human tissues outside the adult brain. Overexpression of RREB-1 protein in TT cells confers the ability to mediate increased transactivation of the CT gene promoter-reporter construct during Ras- or Raf-induced differentiation. These data suggest that RREB-1 may play a role in Ras and Raf signal transduction in medullary thyroid cancer and other cells.

Does the brain influence somatic responses to noxious stimuli during isoflurane anesthesia?

BACKGROUND

Recent evidence suggests that anesthetic action within the spinal cord is important in suppressing somatic responses to painful stimuli. Whether the brain influences this response is not clear. This study was designed to test the hypothesis that the brain affects anesthetic requirements.

METHODS

Six goats were anesthetized with isoflurane. After tracheal intubation and femoral arterial cannulation, bilateral neck dissections were performed to isolate the external carotid arteries and external jugular veins. The occipital arteries were ligated bilaterally. Control isoflurane requirements as defined by the minimum alveolar concentration (MAC) were determined by using a dew-claw clamp as a painful stimulus. Cranial venous blood was drained into a bubble oxygenator in which an isoflurane vaporizer was placed in line with the gas flow, and arterial blood was infused into a carotid artery with a roller pump. This arrangement permitted selective control of the delivery of anesthetic to the head and to the systemic circulation. Isoflurane concentration in the arterial blood delivered to the head was estimated from the isoflurane concentration in the oxygenator exhaust. While isoflurane concentration in the head was maintained at approximately 0.2-0.3%, MAC for the body was determined. After return to the native circulation, MAC was determined again.

RESULTS

During bypass with cranial isoflurane concentration at 0.2-0.3%, all animals showed varying, intermittent degrees of light anesthesia, including spontaneous head movement, chewing, swallowing, and eye opening. Isoflurane MAC was 1.4 +/- 0.2% (mean +/- SD) at baseline, decreased to 0.8 +/- 0.1% during bypass (P < 0.05), and increased to 1.2 +/- 0.2% after bypass (P not significant compared with baseline).

CONCLUSIONS

These results verify the importance of volatile anesthetic action at an extracranial site vis à vis purposeful movement in response to a noxious stimulus. Furthermore, the results confirm that the brain affects anesthetic requirements.

Changes in hepatic iodothyronine metabolism during ontogeny of the chick embryo

As a model of the changes in peripheral iodothyronine metabolism that occur during ontogeny, we have studied the metabolism of 125I-labeled T4 and several of its partially deiodinated derivatives by the liver of the chick embryo. Homogenates of livers obtained from chicks varying in embryonic age from 8 days to the time of hatching (20-21 days) were incubated with various iodothyronines, all labeled with 125I in their outer or phenolic ring. Rates and products of the reactions were analyzed by paper chromatography of whole homogenates. In livers from embryos of all ages studied, the addition of dithiothreitol (DTT; 2 mM) enhanced the rate of metabolism of the iodothyronines T4, T3, and rT3. Marked age-related changes in the metabolism of the iodothyronines were apparent; these were evident in the absence of DTT, but were most clearly seen in specimens to which DTT had been added. rT3 was degraded very rapidly, even in livers from 8-day-old embryos, but its rate of degradation increased progressively with increasing age of the embryo up to the time of hatching. Outer ring (5'-) monodeiodination, giving rise to 3,3'-diiodothyronine (3,3'-T2), was the predominant, and perhaps the sole, pathway of rT3 metabolism throughout this period of embryogenesis. Age-related changes in the metabolism of T4 and T3 were similar to one another, but differed greatly from those seen in the case of rT3. In specimens enriched with DTT, the rates of metabolism of T4 and T3 were moderately rapid in livers from 12-day-old embryos and then increased abruptly, remaining very rapid in livers from embryos through 18 days of age. Rapid degradation of T4 was not due to 5'-monodeiodination, since very little T3 was generated from T4. In addition, since results obtained were similar during incubations under air and N2, oxidative degradation of T4 was apparently not important. Rather, during this period, inner ring (5-) monodeiodination appeared to be by far the predominmant pathway of metabolism of both T4 and T3, leading to the formation of rT3 from T4 and 3,3'-T2 from T3. In livers from 19- and 20 day-old embryos, the latter obtained just before hatching, the overall metabolism of both T4 and T3 slowed abruptly and progressively owing to a decrease in the rate of 5-monodeiodination. Concomitantly, 5'-monodeiodination of T3 and T4 became more prominent, leading to increased generation of T3 from T4. These maturational changes in T4 and T3 metabolism coincided in time with penetration of the air sac by the embryo's beak and initiation of air breathing, a process termed internal pipping. Premature maturational changes in T4 and T3 metabolism, very similar to those that occurred spontaneously in 19- and especially 20-day-old embryos, were induced within 2 days by the single injection of 200 microgram hydrocortisone onto the allantoic membrane of immature embryos. It is concluded that hepatic iodothyronine metabolism in the immature embryo is directed so as to prevent the accumulation of T3 derived from T4...

Artifacts and Pheromone Blends from Nezara spp. and Other Stink Bugs (Heteroptera: Pentatomidae)

Isomeric compounds reportedly released by mature males of Nezara viridula as attractants for conspecific females are evidently artifacts formed by dimerization of (E)-4-oxo-2-hexenal. Additional analyses of the male-specific volatiles from Italian, Australian, Brazilian, and Japanese populations of N. viridula verify that at least two distinctive pheromone strains exist, but an active synthetic pheromone has not yet been developed. Analyses of volatiles from N. antennata and Acrosternum aseadum males are also reported showing that the native Japanese Nezara sp., and species in the sister genus Acrosternum, produce species-specific blends based on the same compounds as N. viridula: (Z)-α-bisabolene (1-methyl-4-(1,5-dim ethyl-(Z)-1,4- hexadienyl)-cyclohexene), and trans- and cis-1,2-epoxides of (Z)-α-bisabolene. The trans-/cis- 1,2-epoxide ratio of N. antennata is within the range found for most N. viridula populations, but the blend from Japanese N. viridula males deviates radically from those of other conspecific populations.

Underutilization of pneumococcal vaccine in nursing home in Washington State: report of a serotype-specific outbreak and a survey

PURPOSE

To describe an outbreak of pneumococcal disease in a Washington state nursing home and to report a survey of pneumococcal vaccine utilization in Washington nursing homes.

PATIENTS AND METHODS

Outbreak. Data were collected from nursing home residents' records. Nasopharyngeal cultures were obtained from residents and staff. Survey. Fifty-four randomly selected Washington nursing homes were surveyed about pneumococcal vaccine utilization and policies.

RESULTS

Outbreak. Three confirmed and 4 possible cases of pneumococcal disease occurred over 9 days among 94 residents; 5 patients (71%) died. Cases were identified among 6 of 42 residents on 1 wing, compared with 1 of 52 on the other 2 wings (relative risk 7.4, 95% confidence interval 1.0, 398.5). Streptococcus pneumoniae serotype 9V was cultured from the blood of 3 confirmed case-patients and the nasopharynx of 2 of 73 residents. Only 7% of residents had received pneumococcal vaccine, including one case-patient who had received 14-valent vaccine without serotype 9V. Survey. Only 22% of residents were reported to have received pneumococcal vaccine; vaccination status was unknown for 66%. Physician discretion determined pneumococcal vaccination in 49 (91%) nursing homes; 9 (17%) had a written policy. Two major barriers to pneumococcal vaccination were cited: low priority among physicians (43%) and difficulty in determining residents' vaccine history (37%).

CONCLUSIONS

A pneumococcal disease outbreak among undervaccinated nursing home residents probably resulted from person-to-person transmission. Pneumococcal vaccine appears to be underutilized in Washington state nursing homes.

A two-colour fluorescence assay for the measurement of syncytial fusion between trophoblast-derived cell lines

Syncytial fusion is a key event in implantation and placentation. Its regulation is only poorly understood. We present a cell-cell fusion assay based on staining of cells in two portions with a green and a red fluorescent cytoplasmic dye that become intracellularly mixed only after syncytial fusion. We quantified cell-cell fusion by fluorescence microscopy in choriocarcinoma cell lines BeWo, JAR and JEG3 and in some non-trophoblastic cell lines and found clear differences in fusion behaviour. Only BeWo cells fused with each other, while the other cell lines tested did not. BeWo cells also fused with all other cell lines tested. The efficiency of cell-cell fusion of BeWo cells was stimulated by forskolin. We tried to correlate messenger levels of syncytin and its receptor RDR with the fusion index of choriocarcinoma cells. BeWo and JAR cells contained readily detectable and forskolin-inducible levels of syncytin mRNA, whereas this messenger was barely detectable in JEG3 cells. RDR transcript levels were similar in all cell lines tested and were unaffected by forskolin treatment. The data suggests that the expression of syncytin and RDR messengers alone does not guarantee successful fusion. The fusion assay presented in this paper is a useful tool to study syncytial fusion in an accurate and quantitative way.

Metastatic malignancy of the cervical spine. A nonoperative history

Of 48 patients with spinal metastases treated at the Kenneth J. Norris Cancer Center at The University of Southern California Medical Center in Los Angeles, California between 1984 and 1987, 19 consecutive patients with cervical metastatic disease were identified and followed until death or remission. Prostate, breast, and lung neoplasms accounted for 57% of the cervical metastases. Associated nonspinal skeletal, extraskeletal, or multiple-level spinal metastases were seen in 95% of patients. Mean time from diagnosis of primary tumor to cervical metastasis was 29 months and mean survival after that was 14.7 months. Pain was the initial symptom in 89% of cases. No patient had neurologic deficit and three (16%) had slight radiographic collapse and deformity. Only one (5%) patient had documented instability. All patients had nonoperative treatment with radiotherapy, chemotherapy, or a combination. Irrespective, the pain recurred in all patients by 6 months. Nonoperative treatment may be appropriate in the absence of significant neurologic deficit or instability. The return of symptoms by 6 months warrants alternative modes of therapy.

Semiochemicals from herbivory induced cotton plants enhance the foraging behavior of the cotton boll weevil, Anthonomus grandis

The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by cotton plants enhanced the attractiveness of the aggregation pheromone emitted by male boll weevils. Behavioral responses of A. grandis to VOCs from conspecific-damaged, heterospecific-damaged (Spodoptera frugiperda and Euschistus heros) and undamaged cotton plants, at different phenological stages, were assessed in Y-tube olfactometers. The results showed that volatiles emitted from reproductive cotton plants damaged by conspecifics were attractive to adults boll weevils, whereas volatiles induced by heterospecific herbivores were not as attractive. Additionally, addition of boll weevil-induced volatiles from reproductive cotton plants to aggregation pheromone gave increased attraction, relative to the pheromone alone. The VOC profiles of undamaged and mechanically damaged cotton plants, in both phenological stages, were not different. Chemical analysis showed that cotton plants produced qualitatively similar volatile profiles regardless of damage type, but the quantities produced differed according to the plant's phenological stage and the herbivore species. Notably, vegetative cotton plants released higher amounts of VOCs compared to reproductive plants. At both stages, the highest rate of VOC release was observed in A. grandis-damaged plants. Results show that A. grandis uses conspecific herbivore-induced volatiles in host location, and that homoterpene compounds, such as (E)-4,8-dimethylnona-1,3,7-triene and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene and the monoterpene (E)-ocimene, may be involved in preference for host plants at the reproductive stage.

Identification of male-specific volatiles from nearctic and neotropical stink bugs (Heteroptera: Pentatomidae)

Males of the Central American stink bug species,Euschistus obscurus, produce an attractant pheromone composed of a blend of compounds characteristic of North AmericanEuschistus spp. and the South American soybean pest,E. heros. The range ofE. obscurus extends into the southern United States, the species is easy to rear, and males produce an exceptionally large quantity of pheromone (>0.5µg/day/male). These factors madeE. obscurus useful for characterizing the novel pheromone components ofE. heros without importing this pest species into the United States.Euschistus obscurus males produce methyl (2E,4Z)-decadienoate (61 %) in abundance, which is characteristic of North American species, and methyl 2,6,10-trimethyltridecanoate (27%), the main male-specific ester ofE. heros. The chirality ofEuschistus spp. methyl-branched esters, and field activity of synthetic formulations, remain to be determined.

Once weekly fluconazole is effective in children in the treatment of tinea capitis: a prospective, multicentre study

In an open, multicentre evaluation carried out in Brazil, Canada and South Africa we have demonstrated that fluconazole 8 mg kg-1 once weekly is effective in tinea capitis caused by Trichophyton and Microsporum species. There were 61 children, aged (mean +/- SE) 5.0 +/- 0.3 years; weight (mean +/- 5.6) 20.0 +/- 0.9 kg; 41 males, 20 females; one Asian, 57 Black, one Caucasian and two Hispanic. The organisms were Trichophyton violaceum (33 patients), T. tonsurans (11) and Microsporum canis (17). The extent of tinea capitis at pretherapy was: mild (18 patients), moderate (30) and severe (13). Patients with tinea capitis due to Trichophyton species were initially treated for 8 weeks with an extra 4 weeks of fluconazole if clinically indicated. All 44 patients with tinea capitis due to Trichophyton species were completely cured (clinically and mycologically) when evaluated 8 weeks after completion of active treatment, following 8 weeks of once weekly dosing in 35 patients and 12 weeks of once weekly dosing in nine patients. In Microsporum canis tinea capitis, an extra 4 weeks was administered at week 12 in patients where it was clinically indicated at the time. Sixteen of 17 patients with M. canis tinea capitis were completely cured (clinically and mycologically) when evaluated 8 weeks following the end of treatment when given for 8, 12 and 16 weeks in 12, one and three patients, respectively. Overall, complete cure (clinical and mycological) occurred in 60 of 61 patients at follow-up 8 weeks from the end of therapy. The duration of once weekly fluconazole in the 60 patients was 8 weeks (47 patients), 12 weeks (10 patients) and 16 weeks (three patients), respectively. Clinical adverse effects consisted of a mild, reversible gastrointestinal complaint in three (4.9%) of 61 children. A laboratory abnormality with elevated liver function tests was observed in one (5.9%) of 17 patients; this was asymptomatic, and reversible. No patient discontinued therapy. The data suggest that once weekly fluconazole dosing is effective, safe and associated with high compliance when used to treat tinea capitis.

Attractant pheromone for nearctic stink bug,Euschistus obscurus (Heteroptera: Pentatomidae): Insight into a neotropical relative

Volatiles fromEuschistus obscurus males were found to be attractive to conspecific females in bioassays. A new type of olfactometer assembled from commercially available glassware was used to bioassay aeration extracts of the Nearctic stink bug,E. obscurus. Fractionated extracts suggest that pheromonal activity is associated with late-eluting, male-specific compounds. Research onE. obscurus offered a means to indirectly study the pheromone of the Neotropical pest species,E. heros, without importing this soybean pest into the United States.

Dual T1/T2 MRI contrast agent based on hybrid SPION@coordination polymer nanoparticles

A novel dual T₁/T₂¹H-MRI contrast agent based on the encapsulation of super-paramagnetic iron oxide nanoparticles (SPIONs) with an iron coordination polymer is proposed.

v-rasH induces non-small cell phenotype, with associated growth factors and receptors, in a small cell lung cancer cell line

Small cell lung cancer (SCLC) tumor progression can involve partial or complete conversion to a more treatment-resistant non-small cell (NSCLC) phenotype. In a cell culture model of this phenomenon, we have previously demonstrated that insertion of the viral Harvey ras gene (v-Ha-ras) into SCLC cell lines with amplification and overexpression of the c-myc gene induced many NSCLC phenotypic features. We now report that the v-Ha-ras gene can also induce morphologic, biochemical, and growth characteristics consistent with the NSCLC phenotype in an N-myc amplified SCLC cell line, NCI-H249. We show that v-Ha-ras has novel effects on these cells, abrogating an SCLC-specific growth requirement for gastrin-releasing peptide, and inducing mRNA expression of three NSCLC-associated growth factors and receptors, platelet-derived growth factor B chain, transforming growth factor-alpha (TGF-alpha), and epidermal growth factor receptor (EGF-R). TGF-alpha secretion and EGF-R also appear, consistent with the induction of an autocrine loop previously shown to be growth stimulatory for NSCLC in culture. These data suggest that N-myc and v-Ha-ras represent functional classes of genes that may complement each other in bringing about the phenotypic alterations seen during SCLC tumor progression, and suggest that such alterations might include the appearance of growth factors and receptors of potential importance for the growth of the tumor and its surrounding stroma.

An adherent subline of a unique small-cell lung cancer cell line downregulates antigens of the neural cell adhesion molecule

Small-cell lung cancer (SCLC) lines are distinguished from non-small-cell lung cancer (NSCLC) lines by their growth in floating aggregates, in contrast to the adherent monolayers formed by NSCLC cells in culture. Of 50 well-characterized SCLC lines recently described by the National Cancer Institute (NCI)-Navy Medical Oncology Branch, only four variant cell lines (SCLC-v) grew as adherent monolayers. One line, NCI-H446, was unique in growing long-term with coexisting floating and surface adherent subpopulations. We have physically segregated these two populations over many passages in vitro to enrich for relatively pure cultures of floating and adherent cells. No differences in c-myc expression, keratin pattern, or cytogenetic appearance were found between the adherent and floating sublines. However, expression of the neuroendocrine marker neuron-specific enolase in the floating cells was three times that found in the adherent cells. The floating subline also had much greater surface expression of neuroendocrine tumor antigens detected by monoclonal antibodies UJ13A and HNK-1, which have been recently shown to detect the neural cell adhesion molecule (NCAM) on SCLC cells. Two other adherent SCLC-v lines were also found to be unreactive with UJ13A and HNK-1, generalizing the association between NCAM expression and the growth of most SCLC cultures as floating aggregates. In conclusion, we have an interesting model to study expression of NCAM as related to the adhesive properties of SCLC cells.

Formation of diiodotyrosine from thyroxine. Ether-link cleavage, an alternate pathway of thyroxine metabolism

Studies were performed to elucidate the nature of the pathway of hepatic thyroxine (T4) metabolism that is activated by inhibitors of liver catalase. For this purpose, the metabolism of T4 in homogenates of rat liver was monitored with T4 labeled with 125I either at the 5'-position of the outer-ring (125I-beta-T4) or uniformly in both the outer and inner rings (125I-U-T4). In homogenates incubated with 125I-beta-T4 in an atmosphere of O2, the catalase inhibitor aminotriazole greatly enhanced T4 degradation, promoting the formation of large proportions of 125I-labeled iodide (125I-I-) and chromatographically immobile origin material (125I-OM), but only a minute proportion of 125I-labeled 3,5,3'-triiodothyronine (125I-T3) (T3 neogenesis). In an atmosphere of N2, in contrast, homogenates produced much larger proportions of 125I-T3, and aminotriazole had no effect. In incubations with 125I-U-T4, under aerobic conditions, control homogenates degraded T4 slowly; formation of 125I-labeled 3,5-diiodotyrosine (125I-DIT) was seen only occasionally and in minute proportions. However, in homogenates incubated under O2, but not N2, aminotriazole consistently elicited the formation of large proportions of 125I-DIT, indicating that the ether link of T4 was being cleaved by an O2-dependent process. Formation of 125I-DIT in the presence of aminotriazole and O2 was markedly inhibited by the substrates of peroxidase, aminoantipyrine, and guaiacol. GSH greatly attenuated the increase in DIT formation induced by aminotriazole, whereas the sulfhydryl inhibitor N-ethylmaleimide (NEM) activated the DIT-generating pathway, even in the absence of aminotriazole. Activation of the in vitro formation of 125I-DIT from 125I-U-T4 was also produced by the in vivo administration of aminotriazole or bacterial endotoxin, an agent that reduces hepatic catalase activity. Studies with 125I-DIT as substrate revealed it to be rapidly deiodinated by liver homogenates under aerobic conditions. Recovery of 125I-DIT from 125I-U-T4 was increased by the addition of the inhibitor of iodotyrosine dehalogenase, 3,5-dinitrotyrosine. However, as judged from studies conducted in parallel with radioiodine-labeled DIT and 125I-U-T4 as substrates, none of the factors that altered the proportion of 125I-DIT found after incubations with 125I-U-T4 did so by altering the degradation of the 125I-DIT formed. The factors that influenced DIT formation from T4 in rat liver had opposite effects on T3 neogenesis. Thus, aminotriazole, endotoxin, NEM, and an aerobic atmosphere, all of which enhanced DIT formation, were inhibitory to T3 neogenesis. In contrast, anaerobiosis and GSH inhibited ether-link cleavage of T4, but facilitated T3 neogenesis. The foregoing results suggest that a pathway for the ether-link cleavage of T4 to yield DIT is present in rat liver. Activity of this pathway, which appears to be peroxidase mediated, is inversely related to activity of the pathway for the T3 neogenesis. It is further suggested that this reciprocity reflects a reciprocal relationship between hepatic GSH and H2O2, the former increasing T3 formation and inhibiting DIT formation, and the latter producing opposite effects.

Prognostic factors for response to chemotherapy containing platinum derivatives in patients with unresectable non-small cell lung cancer. (NSCLC)

PURPOSE

To identify pretreatment variables predicting response to platinum derivatives containing chemotherapy in patients with unresectable non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Eligible patients included in one of the 7 consecutive clinical trials conducted by the European Lung Cancer Working Party between December 1980 and August 1991. All patients received a cisplatin or carboplatin containing chemotherapy. We analyzed 22 potential prognostic factors including sex, age, histology, performance status, weight loss, type of lesions, extent of disease, main metastatic sites and several biological parameters, namely white blood cell count (WBC), neutrophil count, platelet count, hemoglobinemia, creatininemia, serum alkaline phosphatases and LDH.

RESULTS

On 1052 eligible patients. 107 were not assessable for response. The objective response rate was 26% (95% C.I.: 23, 29%). Univariate analysis identified as statistically significantly associated with a higher objective antitumoral response rate the following characteristics: a normal platelet count, the absence of skin metastasis, the absence of adrenal metastasis, a higher creatininemia, a normal hemoglobinemia, an older age and a normal WBC count. On a restricted set of variables including data from 777 patients, a multivariate logistic regression model disclosed age and platelet count as significantly and independently related to response rate.

CONCLUSION

Clinical and demographic characteristics of patients with unresectable NSCLC, as well as routine laboratory parameters, could not accurately predict response to chemotherapy in a population of patients selected for a clinical trial. Future studies on this subject should include more sophisticated variables as new biomolecular makers.

Growth hormone secretion in patients with constitutional delay of growth and pubertal development

Growth hormone levels were measured every 30 minutes during sleep over 9 hours in 20 prepubertal patients with constitutional delay of growth and puberty (CGD) and in 10 age-matched controls, all of whom had had normal GH responses to an orally administered dose of clonidine. We found no significant difference in the mean 9-hour overnight GH concentration between groups (4.5 +/- 1.8 ng/ml (mean +/- SD) in the CGD group, 4.4 +/- 2.8 ng/ml in the control group). Total GH output (258 +/- 99 U vs 222 +/- 135 U), total number of nocturnal GH pulses (3.6 +/- 0.8 vs 3.3 +/- 1.3), mean peak GH response during nocturnal sampling (13 +/- 1.2 ng/ml vs 13.2 +/- 1.3 ng/ml), and basal somatomedin C concentrations were not different in the children with growth delay and controls. We conclude that prepubertal patients with constitutional delay of growth and puberty secrete GH normally and do not seem to have any abnormality in GH regulation.