A genotype-phenotype research strategy for schizophrenia

A research strategy which integrates known biological aspects of schizophrenia is proposed. The strategy includes genotype and phenotype components and emphasizes interactions. Its central feature is the comprehensive diagnostic assessment of patients with schizophrenia. Clinical and laboratory based methodologies are applied within the genotype and phenotype components of the strategy. Examples of research from each area and the potential interactions with other aspects of the strategy are presented. The expectation is that a greater understanding of the pathophysiology of schizophrenia will result from the application of the genotype-phenotype strategy and that consequently more efficacious treatments will ultimately be developed.

Serum thyroxine levels in schizophrenic and affective disorder diagnostic subgroups

Serum free thyroxine (FT4) and total thyroxine (TT4) levels were measured at 2-week intervals during the course of hospitalization in 29 male inpatients in the following four diagnostic groups: paranoid schizophrenia (PS); undifferentiated schizophrenia; bipolar I disorder, manic; and major depressive disorder, endogenous type. The most striking finding was a difference in the direction of both TT4 and FT4 change during clinical recovery in the PS group compared with the other three groups. Analysis of the delta values, representing the change between admission and discharge values, revealed significant differences between the mean rise in the PS group vs. the mean decreases in the other three groups for both TT4 (p less than .0003) and FT4 (p less than .003). For TT4, 75% of the PS group showed a rise during recovery in contrast to 4% of the remaining groups; for FT4, 50% of the PS group showed a rise compared with 14% of the other groups. A significant difference was also observed between the FT4 levels of bipolar I, manic vs. PS patients at the time of hospital admission, which may have potential usefulness in the differential diagnosis of these two disorders. This study emphasizes the importance of exploring more fully the psychiatric significance of thyroxine levels within the endocrinological normal range and of doing longitudinal assessments of thyroxine and symptom changes during clinical recovery in psychiatric disorders.

Molecular genetic studies in schizophrenia

Despite many years of research, the genetic factors in schizophrenia are not well understood. Recent developments in DNA technology allow new methods of testing genetic hypotheses in the etiology of this debilitating disorder. We have found evidence against linkage of schizophrenia in a Swedish kindred to markers on chromosome 5; another research group has reported positive evidence for linkage to this same chromosomal region in British and Icelandic families. This article presents a set of data expanded from our previous report, discusses the issue of heterogeneity, and reviews the current status of linkage studies in schizophrenia.

A field evaluation of air sampling methods for TNT and RDX

A comparative field study was conducted at an ammunition plant to evaluate the use of several sampling techniques for 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The objective was to compare the currently recommended combination Tenax-plus-filter tubes with the older, colorimetric diethylaminoethanol bubbler method which was in use in July 1950 when the American Conference of Governmental Industrial Hygienists (ACGIH) published their first Threshold Limit Values (TLVs). These values included a TLV of 1.5 mg/m3 for TNT. Regular Tenax tubes and 37-mm glass fiber filters also were tested since they also had been used by the United States Army for a number of years. The survey results showed fair agreement between the bubbler and tube methods in those instances where sufficient TNT was present to produce a measurable color in the diethylaminoethanol (DEAE). The glass fiber filters were not satisfactory for TNT retention, but the two types of tubes both were effective. The combination tubes were superior for RDX and appeared to be the best overall sampling medium.

Evidence against linkage of schizophrenia to markers on chromosome 5 in a northern Swedish pedigree

Schizophrenia is a severe mental illness with a typically chronic course affecting nearly 1% of the human population. It is generally accepted that genetic factors have an important pathogenic role in a substantial portion of schizophrenia cases; however, despite decades of family studies, there is no agreed-upon mode of inheritance. The discovery of genetic aetiologic factors and resolution of the inheritance pattern(s) will undoubtably emerge from genetic linkage studies. With these objectives in mind, we undertook a linkage project, starting in 1985, in a previously well-documented kindred from north Sweden. Multipoint linkage analyses were used to screen the proximal long arm of chromosome 5 using restriction fragment length polymorphism (RFLP) markers at five loci and the distal long arm using RFLPs at two loci, one of which was the locus for the glucocorticoid receptor. We found strong evidence against linkage between schizophrenia and the seven loci. These results, together with the positive evidence for linkage of schizophrenia with markers in the proximal long arm of chromosome 5 lead us to conclude that the genetic factors underlying schizophrenia are heterogeneous.

Variability in interpretation of immunohistologic findings in lymphoproliferative disorders by hematopathologists. A comprehensive statistical analysis of interobserver performance

Eight hematopathologists independently reviewed 56 consecutive cases of benign and malignant lymphoproliferative disorders (LPD) to determine: (1) the degree of interobserver agreement on the interpretation of immunologic findings on fresh-frozen sections alone and on that of the immunologic findings in conjunction with corresponding hematoxylin and eosin (H & E)-stained histologic sections; (2) whether prior knowledge of morphologic characteristics influences the interpretation of immunohistologic sections; (3) whether immunologic phenotype could be predicted reliably based solely on study of histologic sections; and (4) the significance of immunologic data as an aid in the interpretation of histologic sections. The study was carried out in three independent review sessions consisting of (1) review of immunohistologic sections only, (2) review of the same immunohistologic sections together with histologic sections, and (3) review of the histologic sections alone. A consensus diagnosis was defined as agreement of five or more pathologists on the final diagnosis and identification of the immunophenotype. When the authors compared the total number of major disagreements in the first review session with those in the second, the accuracy of the determination of immunophenotype in the second session was clearly superior (P less than 0.05). Similarly, the total number of major disagreements in the second review session was significantly lower than that in the third review session (P less than 0.001). When histologic diagnoses in the second session were compared with those in the third session, it became apparent that the immunologic data helped the pathologist to correct major misinterpretations in 14 cases (25%). This study is the first to demonstrate quantitatively that (1) knowledge of morphologic features influences and greatly enhances the accuracy of the interpretation of immunologic findings, (2) the immunophenotype of LPD cannot be predicted based on morphologic findings alone, and (3) immunologic findings improve the accuracy of interpretation of histologic findings in situations in which a diagnosis cannot be made from morphologic features only.

Ovulation induction

Methods to induce ovulation in anovulatory women have blossomed over the last three decades. The introduction of clomiphene citrate in 1960 allowed us for the first time to provoke follicle development in patients with normo or hyperestrogenic forms of anovulation. The development of human menopausal gonadotropins in the early 1960s gave us a much more powerful tool with which to influence ovulation in all forms of ovulatory disturbances. Elucidation of the pulsatile secretion of gonadotropin-releasing hormone together with its isolation and synthesis has allowed us to streamline our methods of inducing ovulation in hypothalamic amenorrheic patients by using endogenous control mechanisms to maximize both safety and effectiveness. However, there are problems yet to solve. Polycystic ovarian disease has long eluded our efforts to resolve its pathophysiology as well as to devise a consistently effective and safe means of treatment. Methods to restore ovulation in patients with polycystic ovarian disease refractory to clomiphene citrate is the quest of future investigations.

Obstetric diagnosis and perinatal mortality

A multidisciplinary team composed of obstetricians, pediatricians, and pathologists examined the causes of 453 consecutive perinatal deaths, which occurred between 1978 to 1982. A clear distinction between obstetric diagnosis and infant cause of death was made, and a prinicpal obstetric and infant diagnosis was assigned to each death. Perinatal death rates by obstetric category were calculated. The rates varied from 6.1 per 1000 births in uncomplicated cases to 217.4 per 1000 births in isolated intrauterine growth retardation. The causes of perinatal death within obstetric categories were tabulated. Nonviability or the complications of prematurity (65%) were the leading causes of death when there was third-trimester bleeding, premature labor, or premature rupture of membranes. Anoxia (59%) was the most frequent cause of death when there was hypertension/pre-eclampsia or other uteroplacental insufficiency states. Death from congenital abnormality accounted for 17.7% of all perinatal deaths. A focus on the causes of perinatal death with obstetric diagnostic categories helps weigh the risk of prematurity versus the risk of anoxia in the management of high-risk gravidas.

Primary culture of squamous head and neck cancer with and without 3T3 fibroblasts and effect of clinical tumor characteristics on growth in vitro

Twenty-one tumors from patients with squamous cell carcinoma of the head and neck (SCC H/N) were cultured with and without 3T3 fibroblasts in order to determine whether, on the basis of improved tissue culture medium, 3T3 cells could be deleted without altering growth and cloning efficiency. Thirty-five additional primary SCC H/N specimens, cultured in the presence of 3T3 fibroblasts, were studied to assess the effect of tumor differentiation, site of primary tumor, and site of specimen procurement on growth. The authors conclude that 3T3 cells remain essential for optimal growth and cloning efficiency. Also, 3T3 cells improved the number of successful cultures by 33% to 100% depending on the plating density, and cloning efficiency was improved by 50% in the presence of 3T3 cells. Growth did not correlate with tumor differentiation or site of origin of the tumor specimen. Culture of specimens from the primary site resulted in growth significantly more frequently than culture of specimens obtained from metastatic neck nodes.

Culture of squamous head and neck cancer on 3T3 fibroblasts following isokinetic velocity sedimentation

Growth in culture of squamous head and neck cancer is hampered by microbial contamination, low plating efficiency, and cellular heterogeneity within tumors. Furthermore, clumps of cells must be removed if plating efficiency is to be accurately determined. Isokinetic velocity sedimentation was applied to 44 primary tumor specimens in an effort to minimize these problems. Seven fractions were evaluated for cell number, clump number, cell viability, clonogenic growth, plating efficiency, and microbial overgrowth. Unseparated specimens were simultaneously cultured. Microbial growth was significantly associated with the highest gradient fraction. Clumps were significantly associated with the lowest gradient fraction. Colony formation was significantly associated with middle gradient isokinetic velocity sedimentation, although seven specimens grew only when fractionated, suggesting the possibility of inhibitor cells within the tumor specimen.

NonHodgkin's lymphomas of the upper aerodigestive tract and salivary glands

The symptoms, signs, diagnosis, work-up, pathology, and treatment of nonHodgkin's lymphomas of the upper aerodigestive tract and salivary glands are described.

Dominance hierarchies in psychotherapy groups

For a social group to develop, two opposing adaptive processes must be reconciled—mechanisms for developing cohesion and mechanisms for establishing a dominance hierarchy. The formation of stable groups provides significant evolutionary advantages: a source of protection, increased reproductive opportunities, and a larger store of survival strategies than any one individual could encompass. A recent theory of human evolution (Reynolds, 1981) stresses that social behaviour would seem to be the most likely single cause of the origin of human intelligence, if one origin must be isolated. Current interest in the biological basis of behaviour has been focused particularly on specific diagnostic categories and biochemical mechanisms. This paper reviews a different research tradition, based on ethological principles, and applies the findings to an understanding of human group behaviour.

Effect of mode of delivery on morbidity and mortality of infants at early gestational age

The effect of mode of delivery on the mortality and morbidity of 26- to 32-week neonates was studied. Five hundred six consecutive deliveries at 26 to 32 weeks' gestation were reviewed. The populations were divided into high-risk and low-risk neonates by evaluation of antepartum variables known to increase neonatal risk, ie, abruptio placenta. One hundred ninety-six infants were classified as low risk. In this group, 124 vaginal and 72 cesarean section deliveries were compared using demographic, peripartum, and neonatal variables. Cesarean delivery was associated with highly significant maternal morbidity, including a 30% incidence of vertical uterine incision. No difference in neonatal mortality was shown. Cesarean delivery was associated with lower one-minute Apgar scores and a greater incidence and severity of hyaline membrane disease. No neonatal differences were shown in the incidence of trauma, intraventricular hemorrhage, or seizures. This study does not support cesarean delivery of all tiny neonates.

Positive correlation between mature amniotic fluid optical density readings and the absence of neonatal hyaline membrane disease

Fetal pulmonary maturity is generally determined by analyzing amniotic fluid for surfactants. This task is accomplished by lipid extraction of the fluid and resolution, identification and quantitation of the isolated lipids with thin-layer chromatography. These methods are lengthy, cumbersome and often not available on demand. A quick, simple, reliable and economical test therefore would be highly desirable. We have been able to correlate an optical density (OD) reading of amniotic fluid at 650 nm greater than or equal to 0.15 with the absence of hyaline membrane disease (HMD). For 428 fluids in which an OD reading of greater than or equal to 0.15 was found and delivery occurred within 48 hours, HMD was present in only two infants. The accuracy of the test was 99.53% , with a false-positive rate of 0.47%. With the use of this simple and accurate test one can satisfy the requirement of an on-demand test to determine fetal pulmonary maturity.

Pulmonary lymphomas and other pulmonary lymphoid lesions. A clinicopathologic and immunologic study of 64 patients

Sixty-four patients with lymphoid lesions involving the lung were separated into three groups. In 32 patients, the predominant lymphoid cell population consisted of small, mature-appearing round lymphocytes with or without plasmacytoid features. This group, designated small lymphocytic proliferation (SLP), represents a heterogeneous group of pulmonary lymphocytic lesions including small lymphocytic lymphoma, lymphocytic interstitial pneumonia, and lymphoid hyperplasia (pseudolymphoma). Thirteen SLP patients were identified as having small lymphocytic lymphoma on the basis of monoclonality, progressive disease in other sites, or both. This group was morphologically identical to the remainder of the SLP patients, except for a higher incidence of plasmacytoid features (P = 0.003) and a greater degree of mast cell infiltration (P less than 0.05). Four of these 13 patients subsequently developed an aggressive large cell lymphoma resulting in death in three patients. The median survival for all of the SLP patients has not yet been reached. Patients in whom a monoclonal cell population could be established showed a slightly worse prognosis of borderline statistical significance (P = 0.09); however, the presence of a serum monoclonal gammopathy conveyed a significantly worse prognosis (P = 0.003). The remaining two groups of patients had various forms of malignant lymphoma other than the small lymphocytic type. One group of 12 patients, designated as having presumed primary lymphoma limited to one or both lungs (PL), had a prolonged course with a median survival of 117 months. The remaining 20 patients had disseminated lymphoma also involving lung (DL); DL patients had a shorter median survival of 33 months.