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Cystic fibrosis is the most frequently occurring lethal hereditary disorder among whites. Many persons with cystic fibrosis now live into their adult years, and some cases are not diagnosed until adulthood. As a result, the disorder is no longer rare in adults. Respiratory symptoms and findings usually predominate, but a host of other complications that arise in adults also present therapeutic challenges to physicians. While no cure is yet available for cystic fibrosis, genetic counseling can help couples determine their relative risk for parenting a child with the disorder.

New methods for studying the genetic information of humans in health and disease are emerging from basic science laboratories. Because these approaches are yielding fundamental insights for diagnosing and treating disease, it is important that practitioners begin to understand these methods and how they are used. Methods for genetic analysis using recombinant DNA techniques consist of isolation, separation, propagation in microorganisms and molecular hybridization of DNA. The study of RNA allows determination of gene expression. These methods are being used to understand cancer, identify hereditary illness, produce pharmaceuticals and diagnose common clinical problems, such as infectious diseases.

The polymorphic DNA probe D3S3 was assigned to 3p14 by molecular hybridization using a human chromosome 3/hamster somatic cell hybrid deletion panel. This is the first regional assignment of a polymorphic probe to the short arm of chromosome 3. This probe appears to be proximal to the chromosome 3 fragile site and, therefore, may prove useful in characterizing the 3p chromosomal aberrations that occur in various malignant diseases.

A series of human chromosome 3-specific DNA fragments isolated and characterized from a lamda phage genomic library were regionally localized on human chromosome 3. This was accomplished using filter hybridization blot analysis of a human chromosome 3 hybrid cell deletion mapping panel. Twenty-three new anonymous DNA fragments were assigned to one of four physical regions of chromosome 3. Seventeen DNA fragments were mapped to the long arm of chromosome 3, including one DNA fragment that demonstrated a restriction fragment length polymorphism (RFLP). Five DNA fragments were assigned to 3p14.2----pter, including one highly polymorphic fragment sublocalized at 3p25----pter by in situ hybridization. This DNA fragment is the second reported distal 3p polymorphic probe. One DNA fragment was localized to 3p14----p14.2. In addition, three fragments previously assigned to chromosome 3 were confirmed. Polymorphic DNA probes DNF15S2 (formerly D1S1) and D3S2 were mapped to 3p14.2----pter. The previous 3p25 in situ localization of the c-raf-1 oncogene was supported by deletion panel mapping. The physical localization of these twenty-three new DNA fragments has more than doubled the number of cloned DNA fragments assigned to chromosome 3. These and future regional assignments of DNA fragment probes will facilitate construction of both a physical and genetic linkage map of chromosome 3. They may also be useful in characterizing the chromosomal and molecular aberrations involved in small-cell lung cancer (SCLC), renal cell carcinoma, other malignancies, and the 3p14.2 common fragile site.

Ear oximetry offers a noninvasive method of determining and monitoring oxygen saturation in arterialized capillary blood. A new apparatus has recently been developed which provides improved accuracy as well as increased ease of use. We have found it to be at least as accurate as the American Optical oximeter which measures oxygen saturation directly from arterial blood. It has proved to be of value in clinical situations such as monitoring critically ill patients (particularly those being mechanically ventilated) and patients undergoing treadmill exercise or fiberoptic bronchoscopy and in the diagnosis of disorders characterized by periodic hypoxia.

Fusion of an auxotrophic mutant hamster cell with the skin fibroblasts of a child with the Wilms' tumor-aniridia association produced clones which, on the one hand, contained the child's normal chromosome 11 and, on the other, the chromosome 11 with the 11p13 deletion associated with the syndrome. Both hybrids were positive for human LDH-A by enzymatic assay. Clones containing the normal human chromosome 11 were killed by a cytotoxic monoclonal antibody to a cell surface antigen previously mapped to the 11p13----11pter region of chromosome 11. Clones with the abnormal 11 were not killed. Thus, we have produced hybrids from the same patient distinct from each other on the basis of their chromosome 11. These hybrids have been used to map the locus for a cell surface antigen to the deleted region on chromosome 11 of a patient with the Wilms tumor-aniridia association. The linkage between this antigen and the syndrome should be helpful in further study of the genetics of this disease. In addition, we have found that the c-Ha-ras-1 oncogene is distal to the p13 region of chromosome 11 and the position of insulin and beta-globin on the chromosome. Finally, by producing segregants of the hybrids containing the abnormal chromosome 11, we have provided evidence that chromosome 11-associated c-Ha-ras-1 is syntenic with chromosome 11 and not moved to a different portion of the genome.

Phosphorylation analysis of CHO mutants selected for unresponsiveness to the Reverse Transformation reaction of cAMP derivatives has been carried out by 2D gel electrophoresis in hopes of finding mutants differing from the wild-type cell in a minimal number of such phosphorylations. Seven differences in protein phosphorylations in the parental CHO cell have been identified as a result of treatment with db-cAMP. db-cAMP-unresponsive mutants of two kinds have been found: One type has lost all seven of the phosphorylation changes induced by db-cAMP in the wild-type cell. The other type which is equally resistant to the Reverse Transformation response differs from the parental cell in only one (or possibly two) phosphorylation(s) involving a 55 000 D protein. This protein may, therefore, be directly related to the events of Reverse Transformation.

As an initial step in gaining a better understanding of the important clinical properties that vary between strains of mycobacteria, we attempted to find molecular markers that would define different strains of Mycobacterium tuberculosis. We used restriction fragment analysis with the endonuclease MboI and hybridization with total M. tuberculosis DNA to examine DNA differences between 15 strains of M. tuberculosis. We were able to identify different strains using this method. In order to assess the sensitivity of this method in identifying different strains, we compared it with phage typing. The 2 methods appear to be similar in sensitivity and also to be complementary. There were 2 examples where restriction fragment analysis did not separate strains with different phage types. In addition, there were 2 examples where phage typing did not separate strains with different restriction patterns. Finally, there were 2 epidemiologically unrelated strains with the same restriction pattern and the same phage type. This method of restriction fragment analysis of chromosomal DNA is potentially useful for epidemiologic studies of tuberculosis. Additionally, by analyzing the genome of M. tuberculosis, molecular markers may well be defined that will be useful in discovering the pathogenesis of the clinical properties of M. tuberculosis, which previously have been poorly understood.

Lung cancer is the predominant fatal neoplasm of our time, and SCLC, which accounts for about 25% of all lung cancer, if untreated results in death in about 3 months. Currently employed aggressive combination chemotherapy has allowed a 4- to 5-fold improvement in median survival over untreated patients. Ten to 20% of patients with limited disease can be expected to have a long-term (2-yr) survival. The majority of patients, however, have extensive disease. For these patients the median survival is about 7 months. Less than 2% survive 2 yr. During the last 10 yr, experience in the treatment of thousands of patients has been reported. These trials, using a large variety of drug combinations, doses, and schedules as well as multiple modalities including radiotherapy, surgery, and bone marrow transplantation, demonstrate that a plateau has been reached with our present therapeutic approach. The development of new effective therapeutic strategies as well as prevention of SCLC require a better basic understanding of the cellular pathophysiology of the disease. A consistent chromosomal abnormality has been associated with SCLC. This may provide new insight into predisposition and pathogenesis of SCLC. How this chromosomal abnormality relates to loss of control of cell growth is under intense investigation. Similarly, during the past 3 yr, the identification of growth regulatory oncogenes has greatly improved our understanding of malignancy. The discovery that metastatic cells escape immune surveillance has led to attempts at modulating antigenic expression. The modulation of cellular antigenic expression may facilitate the destruction of tumor cells by host defense mechanisms. The understanding of the genetic basis of drug resistance may lead to approaches that prevent or delay resistance. This century has witnessed the emergence of SCLC as an important fatal neoplasm. It has also been during this time that another, formerly dominant pulmonary condition, tuberculosis, has been controlled. The reduction of tuberculosis was accomplished by a combination of scientific understanding, beginning with the discovery of Koch's bacillus, and public health measures. Perhaps a similar parallel for SCLC as well as other forms of cancer will be written. Basic cellular investigations with the new tools of molecular biology as well as measures to control exposure to predisposing environmental factors such as component of cigarette smoke may one day lead to control of SCLC.

One hundred eighty-three human single copy clones were isolated from the Livermore Laboratory chromosome 11 library (ID code LL11NSO1) and 112 of them were mapped to chromosome 11. Using a panel of somatic cell hybrids segregating chromosome 11 translocations and short arm deletions, 54 of the clones were assigned to one of nine segments on the short arm of chromosome 11; the remainder were assigned to the long arm. Nine of these clones map to 11p13, and four of the nine [57(D11S89), 530(D11S90), 706(D11S93), and 1104(D11S95)] are confined to the same segment within p13 that contains catalase (CAT), the beta subunit of follicle stimulating hormone (FSHB), and the Wilms' tumor-aniridia (WAGR) gene complex.

A decreased metabolic rate has been associated with decreased ventilatory response to hypoxia and hypercapnia, and also with starvation. We fed a 500-calorie carbohydrate diet with supplemental electrolytes, designed to simulate alimentation by usual intravenous fluids, to seven normal subjects for 10 days to determine the effect of semi-starvation on metabolic rate and ventilatory responses. By the 10th day metabolic rate was significantly decreased, and hypoxic ventilatory response decreased to 42% of control (P less than 0.05). In two subjects, hypoxic ventilatory response was virtually abolished at day 10. These changes reversed toward normal with refeeding. The decrease in hypoxic ventilatory response response was significantly (P less than 0.01) related to the decrease in metabolic rate. Hypercapnic ventilatory response, measured as the slope of the ventilatory response to hypercapnia, decreased slightly but not significantly. The decrease in hypoxic ventilatory response seen during semi-starvation may contribute to the hypoxemia and respiratory failure subsequent to caloric restriction.

Three instances of intense laryngospasm and bronchospasm occurred as a result of fiberoptic bronchoscopic examination in three patients with quiescent bronchial asthma. The indications for the procedure were hemoptysis in one patient and lobar collapse in two. It is likely that vagally mediated reflex laryngospasm and bronchoconstriction occur when irritant receptors are mechanically stimulated by the bronchoscope. Therefore, in the asthmatic population with its increased airway reactivity, indications for fiberoptic bronchoscopy should be absolute, and the procedure should be performed under optimal conditions. A rationale for minimizing the risk of this procedure in patients with bronchial asthma is discussed.

The traditional methods used in identifying mycobacteria, such as acid-fast bacillus stains and culture, are often time-consuming, insensitive, and nonspecific. As part of an ongoing program to improve diagnosis and characterization of mycobacteria, we have found that deoxyribonucleic acid (DNA) hybridization techniques using isotopically labeled, single-stranded, total DNA can be used to detect as little as 10(-4) micrograms of Mycobacterium tuberculosis (MTb) DNA. This amount of DNA represents approximately 2 X 10(4) genomes. We have also shown the MTb DNA is sufficiently different from the DNA of non-mycobacterial microorganisms such that cross-hybridization with MTb DNA does not occur under the hybridization conditions we employed. We speculate that DNA hybridization techniques may allow the rapid, sensitive, and specific identification of mycobacteria.

The use of nick translation of cloned DNA segments followed by separation on low-melting-temperature agarose has been used to obtain multiple radiolabeled DNA probes from a single nick-translation procedure. This technique avoids gel matrix inhibition of enzymatic reactions. Examples of the utility of this procedure are presented and the advantages and drawbacks discussed.

Patients with factitious illness present a particular challenge. Because they may be clever in their deception, they may be difficult to recognize as the fabricators of their apparent medical problem(s). Findings vary from relatively simple problems such as fever to more complex and often dramatic complaints of bleeding and pain. Differential diagnosis should include other, often more easily managed disorders such as somatoform disorders, malingering, antisocial personality, and schizophrenia. Because no definitive treatment exists, patients often consult many physicians, often in diverse geographical locations.

Somatic cell genetic analysis of mutants of Chinese hamster ovary cells with deficient purine synthesis and of hybrids between these mutants and human cells is described. Data are presented substantiating that two genes for enzymes of purine synthesis, AdeC and AdeG, can be coordinately regulated in mammalian cells. Analysis of a human-hamster hybrid cell, Ade C/21, which contains a normal complement of hamster chromosomes and human chromosome 21 as its only human genetic component recognizable by electrophoretic and immunogenetic techniques demonstrates that genes associated with the presence of human chromosome 21 and required for the synthesis of specific polypeptides and specific human lethal cell surface antigens can be detected in these hybrids.

Normal cells have only a finite life span before they die. The process known as aging may occur as a result of continued damage to the cell or as a result of expression of predetermined information within the genetic structure of the cell. Both processes lead to progressive cellular dysfunction which is evidenced by the organs of the body as aging. By understanding how individual cells age we will gain insight into how the body as a whole ages. The impact of such knowledge on science and society is a matter of both conjecture and concern.

DNA molecular biology is becoming increasingly important in clinical medicine. It has provided a new method to diagnose an inherited pulmonary disease in which the biochemical defect has been defined. Alpha-1-antitrypsin deficiency can now be diagnosed by direct analysis for the disease gene. In cystic fibrosis, another inherited pulmonary disease, the biochemical defect has not yet been defined. However, the search has been narrowed. The cystic fibrosis genetic defect has recently been localized to the long arm of chromosome 7. Because polymorphic DNA markers (RFLPs) are available for this region of chromosome 7, it is now often possible, using linkage analysis, to trace the inheritance of the cystic fibrosis gene(s) in families known to have cystic fibrosis. When the cystic fibrosis genetic defect is defined, it will then be possible to look directly for the disease gene. Finally, the greatest impact in clinical medicine may well be the development of rapid DNA hybridization techniques to diagnose infectious diseases that currently take days to weeks to diagnose.

Unbalanced interstitial deletions of the p13 region of human chromosome 11 have been associated with congenital hypoplasia or aplasia of the iris, mental retardation, ambiguous genitalia, and predisposition to Wilms tumor of the kidney. Utilizing somatic cell hybrids containing either the normal or abnormal chromosome 11 from a child with Wilms tumor and aniridia, we previously mapped the E7 cell-surface antigen to the 11p1300-to-11p15.1 region. To localize even further the site of this antigen on chromosome arm 11p, we have produced somatic cell hybrids from the fibroblasts of a second child with Wilms tumor and aniridia and a different deletion of 11p [46,XY, del (11)(pter----p14.1::p11.2----qter)]. Furthermore, the normal and deleted chromosome 11 could also be distinguished on the basis of a restriction fragment length polymorphism for the beta-globin gene. Hybrid cells containing the deleted chromosome were not killed in the presence of complement and the E7 monoclonal antibody (which recognizes E7 cell surface antigen), while hybrid cells containing the patient's normal chromosome 11 were killed. Thus, expression of the E7-associated cell-surface antigen can be mapped to the 11p13 region, and it appears to be a potential marker of the chromosome abnormality associated with aniridia-Wilms tumor.

Twenty-eight patients with advanced emphysema and/or chronic bronchitis and severe airflow obstruction were randomly assigned to receive either bitolterol or isoproterenol aerosol delivered by a metered dose device which was administered three times daily. Randomization resulted in similar patients with like degrees of airflow obstruction and responsiveness to a test dose of inhaled bronchodilator. Significantly greater improvement in airflow was achieved by administration of bitolterol compared to isoproterenol. Pharmacologic responses continued after 90 days of daily dosing. Both drugs were well tolerated and side effects included mild degrees of tachycardia for both drugs. Two patients assigned to isoproterenol stopped therapy during the study due to side effects. This study indicates that bitolterol is more effective than isoproterenol in degree and duration of bronchodilatation in patients with advanced chronic obstructive pulmonary disease.

The human transferrin receptor is an integral membrane glycoprotein of 180,000 molecular weight (mol. wt.) formed from two subunits of 90,000 mol. wt. A clone panel of Chinese hamster-human somatic cell hybrids was screened using a single cell plating cytotoxicity assay and rabbit antiserum raised to purified human transferrin receptor. Chromosome 3 displayed the highest rate of concordance with the presence of human transferrin receptor, as assayed by cytotoxicity. Antitransferrin receptor serum-resistant segregants of chromosome 3 positive, receptor-positive hybrids were selected, using antiserum and complement. The segregants consistently lost chromosome 3. 125I human transferrin binding studies confirmed synteny between the functional human transferrin receptor and chromosome 3. Examination of hybrids with either translocated or deleted chromosome 3's allows regional mapping to 3q(22-ter).