Histologic comparison of regeneration in human intrabony defects when osteogenin is combined with demineralized freeze-dried bone allograft and with purified bovine collagen

A bone-inductive protein, osteogenin, has been isolated from long bones of humans and offers promise as a grafting material. Studies, however, suggest that osteogenin must be combined with a bone-derived matrix in order to initiate bone differentiation. The purpose of this study was to determine if osteogenin combined with demineralized freeze dried bone allograft (DFDBA), a bone-derived matrix, and with a bovine tendon-derived matrix will enhanced regeneration of intrabony defects in humans. The tendon-derived matrix and DFDBA used alone served as controls. The ability of each material to form a new attachment apparatus was evaluated independently in submerged and nonsubmerged environments in 2 patient populations. Lymphocyte testing was performed to assess development of an immune reaction to osteogenin. The most apical level of calculus on the root served as the histologic reference point to measure regeneration. Biopsies were obtained at 6 months and regeneration was measured histomorphometrically by 2 blinded evaluators. Serial sections from 36 submerged defects in 8 patients and 50 nonsubmerged defects in 6 patients were submitted for statistical analysis. Mean results indicate that osteogenin combined with DFDBA significantly enhanced regeneration of a new attachment apparatus and component tissues in a submerged environment. DFDBA plus osteogenin and DFDBA alone formed significantly more new attachment apparatus and component tissues than either the tendon-derived matrix plus osteogenin or the tendon-derived matrix alone in both submerged and nonsubmerged environments. There were no significant differences between the tendon-derived matrix plus osteogenin and the tendon-derived matrix alone in either the submerged or nonsubmerged environment. Osteogenin does not impair normal lymphocyte blastogenesis at 6 months postsurgical challenge.

Prokinetic effect of AS-4370 on gastric emptying in healthy adults

The effect of AS-4370 on gastric emptying was investigated in healthy adults using 99mTc-DTPA. Single doses of AS-4370 2.5, 5 or 10 mg or placebo were administered to 12 subjects in a controlled, double-blind, cross-over study. Tests were performed twice weekly in each subject. Thirty min after administration of test drug or placebo, each subject swallowed a bun and orange juice containing 200 microCi nuclide. The radioactivity of the gastric content was measured for 40 min and the activity of the residue was expressed as a percentage of count at the initiation of measurements. The percentage radioactivity, AUC and gastric emptying time fitted by a power exponential curve, were analyzed. No significant difference was observed between the three dose levels of AS-4370 and placebo in half emptying time. However, decreases in the percentage of radioactivity with time were noted; 5 mg at 10 to 16 min and 10 mg at 8 to 24 min after the start of recording. Lower AUCs after 5 mg and 10 mg compared to placebo were also found. The half emptying time was also shorter after 5 mg and 10 mg than placebo. There was no difference in these parameters between 2.5 mg and placebo. The results indicate that AS-4370 5 and 10 mg but not 2.5 mg accelerates gastric emptying in healthy adults.

Mutations that affect the folding of ribose-binding protein selected as suppressors of a defect in export in Escherichia coli

It has been proposed (Randall, L. L., and Hardy, S. J. S. (1986) Cell 46, 921-928) that export of protein involves a kinetic partitioning between the pathway that leads to productive export and the pathway that leads to the folding of polypeptides into a stable conformation that is incompatible with export. As predicted from this model, a decrease in the rate of export of maltose-binding protein to the periplasmic space in Escherichia coli resulting from a defect in the leader sequence was able to be partially overcome by a mutation that slowed the folding of the precursor, thereby increasing the time in which the polypeptide was competent for export. (Liu, G., Topping, T. B., Cover, W. H., and Randall, L. L. (1988) J. Biol. Chem. 263, 14790-14793). Here we describe mutations of the gene encoding ribose-binding protein that were selected as suppressors of a defect in export of that protein and that alter the folding pathway. We propose that selection of such suppressors may provide a general method to obtain mutations that affect the folding properties of any protein that can be expressed and exported in E. coli.

Separation of carbohydrate-mediated microheterogeneity of recombinant human erythropoietin by free solution capillary electrophoresis. Effects of pH, buffer type and organic additives

Free solution capillary electrophoresis has been investigated as an alternative to isoelectric focusing for the separation of the glycoforms of recombinant human erythropoietin (r-HuEPO), a primary regulator of erythropoiesis. A systematic approach was used to study the effect of pH, buffer type and organic modifiers on the resolution of the microheterogeneity of erythropoietin. The main factors for improving the resolution were the regulation of the electroosmotic flow of the running buffer and the reduction of solute-wall interaction. The best resolution of the glycoforms of r-HuEPO was obtained with a mixed buffer pH 4.0 (100 mM acetate-phosphate, 10 h preequilibration time).

Enhanced stability of subtilisin by three point mutations

This study was undertaken to characterize the effect of three point mutations made on aprA-subtilisin on the stability of the protein to both heat- and detergent-induced denaturation. Asparagine residues at positions 109 and 218 were replaced with serine residues to prevent the possible cyclization between these asparagines and the adjacent glycine residues and hence to increase the long-term stability. The effect of these substitutions on conformational stability was examined by thermal denaturation. At high calcium concentrations, the Ser109-substituted analog showed a 3 degrees C higher transition temperature than that of aprA-subtilisin, while the Ser218 substituted analog had a 4 degrees C higher transition temperature. The analog with both changes had a 7 degrees C higher transition temperature than that of the original aprA-subtilisin, indicating that the contributions of the individual mutations were additive. The analog with both mutations also exhibited increased stability in the presence of sodium dodecyl sulfate (SDS) when compared to aprA-subtilisin. In addition to the above two mutations, the asparagine at position 76, located in the high affinity Ca(2+) binding loop of subtilisin, was changed to aspartic acid. The effect of this mutation on the thermal stability of the protein was examined at different calcium concentrations. The analog with all three mutations exhibited little dependence on calcium concentration below 1 mM levels, while the proteins without the mutation at asparagine-76 displayed a strong dependence of melting temperature on Ca(2+) concentration in this range. At much higher calcium concentrations, the analog with three mutations showed an increase in stability similar to that observed with aprA-subtilisin. The analog with three mutations also exhibited greater stability to SDS-induced denaturation than both aprA-subtilisin and the Ser109- and Ser218-substituted analogs. The activation energy barrier for loss of structure in 1% SDS for the analog with all three mutations was increased over that for aprA-subtilisin by 16 kcal/ml. These results suggest that the mutation of asparagine-76 to aspartic acid increases the affinity of the primary Ca(2+) binding site.

Functional role of mucoid exopolysaccharide (alginate) in antibiotic-induced and polymorphonuclear leukocyte-mediated killing of Pseudomonas aeruginosa

We evaluated in vitro the functional role of mucoid exopolysaccharide (MEP) of Pseudomonas aeruginosa in blocking antibiotic-induced and polymorphonuclear leukocyte (PMN)-mediated pseudomonal killing. The serum-resistant P. aeruginosa isolates used were mucoid strain 144MR and its nonmucoid revertant, strain 144NM. By timed kill curves, early bacterial effects of amikacin against mucoid strain 144MR were substantially less than those observed with nonmucoid strain 144NM; this effect was reversible with enzymatic hydrolysis of MEP of strain 144MR by alginase. Also, early tobramycin uptake (15 to 30 min) by mucoid 144MR cells was less than that seen with nonmucoid strain 144NM; pretreatment of 144MR cells with alginase substantially enhanced early tobramycin uptake compared with untreated 144MR cells (P = 0.08). In strain 144NM (but not in strain 114MR) there was a notable postantibiotic leukocidal enhancement effect manifested by increased nonopsonic killing following brief exposure of these cells to supra-MIC amikacin; pretreatment of strain 144MR with alginase rendered these cells more susceptible to amikacin-induced postantibiotic leukocidal enhancement. Similarly, direct PMN-mediated nonopsonic killing of mucoid strain 144MR was significantly less than that observed with strain 144NM (P less than 0.05); pretreatment of 144MR cells with alginase rendered this strain equal to strain 144NM in susceptibility to nonopsonic killing. In addition, exogenous sodium alginate or extracted MEP of strain 144MR interfered with effective nonopsonic killing of strain 144NM by PMNs. Studies also indicated that mucoid strain 144MR was phagocytosed significantly less well than its nonmucoid mate (P less than 0.00001), an effect reversed by pretreatment of the mucoid cells with alginase. These data confirm that P. aeruginosa MEPs functionally decrease the uptake and early bactericidal effect of aminoglycosides in vitro and interfere with effective PMN-mediated nonopsonic phagocytosis and killing of mucoid strains.

Effect of transcription promoters on the optimal production of secreted protein in fed-batch reactors

Production of heterologous proteins by yeast secretion imposes additional factors that need to be considered, which do not appear with production by direct expression. These include additional intracellular polypeptide processing dynamics through the secretory organelles and the protein concentration in the culture medium, which is the usual final destination of the product. Optimal control theory is applied to optimize fed-batch production of secreted protein. We maximize an objective function that includes both total production rate and product concentration. A mutant invertase is chosen as the model heterologous secretory protein. Optimal control control strategies have been obtained for the use of two different promoters for the gene transcription, a dere-pressible SUC2 promoter and a strong glycolytic GPD promoter. With the use of the strong GPD promoter, achieving maximum production occurs on the singular arc of maximum specific growth rate. As the object switches to maximum product concentration, operation occurs for longer periods of time at a slow glucose singular arc condition. The optimal control for maximizing protein production with the weak SUC2 promoter requires transitions between high and low glucose concentrations associated with multiple distinct singular arc conditions. For maximum product concentration, the high concentration branches of the singular arc supporting maximum growth rate and maximum secretion rate disappear. Operation stays essentially on the low glucose concentration branch of the singular arc, which maximizes the protein production rate and minimizes the dilution of the broth product concentration.

TDAT--time domain analysis tool for EEG analysis

An interactive design and analysis tool for displaying and quantifying multiple channels of data is presented. The system allows one to easily visualize multiple data channels and simultaneously observe the effects of filters on the data and to evaluate signal detection algorithms. The software is designed for a workstation environment; it will find application in a variety of applications where one needs to simultaneously visualize multiple data channels. TDAT is being used for the design and evaluation of filters and detection algorithms for electroencephalogram (EEG) waveforms, and it is serving as a prototype of a paperless system to be used by electroencephalographers. This paper describes the general software structure of the system and illustrates many of the system features with examples.

[Successful treatment by using a pedicled omental flap for mediastinal infection in the presence of a external valved conduit]

Mediastinal infection is one of serve and fatal complications after cardiac surgery, especially in the presence of an artificial graft. A case of successful treatment by using a pedicled omental flap for mediastinal infection in the presence of an external valved conduit is reported. a 10-year-old girl who had implanted the 12 mm porcine valved conduit for truncus arteriosus at age 9 months, underwent replacement of the old conduit with a 18 mm valved conduit. On the 9th postoperative day, as soon as mediastinal infection was proved by positive culture of the drainage from the chest tube, a reoperation was performed to debride and irrigate the mediastinum. Irrigation with povidone-iodine and antibiotics was continued for 3 weeks until improvement of CRP levels and negative drainage cultures. Then the heart and the valved conduit were wrapped with the pedicled omental flap and the skin was closed. She was without any evidence of infection for 3 months after operation. Use of a pedicled omental flap might be an effective method for treatment of mediastinal infection in the presence of an external conduit.

Drug testing at the 10th Asian Games and 24th Seoul Olympic Games

Drug testing (doping test) procedures in the 1986 10th Asian Olympic Games and 1988 24th Seoul Olympic Games are reported. The International Olympic Committee Medical Commission (IOC-MC) conducted its first doping tests at the 1968 Olympics in Grenoble. With the guidance of the International Olympic Committee (IOC), the Olympic Council of Asia (OCA) introduced doping tests at the 1986 10th Asian Olympic Games in Seoul, Korea, September 21st to October 5th, 1986. 585 samples were tested at the Doping Control Center, Korea Advanced Institute of Science and Technology (DCC/KAIST), for stimulants, narcotics, anabolic steroids, and beta-blockers by gas chromatography/mass spectrometry, high pressure liquid chromatography, and fluorescence polarization immunoassay. These tests covered about 100 different drugs and another 400 as metabolites in addition to pharmacologically related substances. For the Seoul Olympic Games from September 17 to October 2, 1988, the IOC-MC with the DCC/KAIST conducted doping tests on 1601 samples for stimulants, narcotics, beta-blockers, diuretics, and anabolic steroids using GC, HPLC, GC/MSD, GC/MS, LC/MS, and TDx.

Vertical dimensional changes of the lips in the North American black patient after four first-premolar extractions

The purpose of this investigation was to evaluate the vertical dimensional changes of the lips in the North American black patient after four first-premolar extractions. A sample of 15 patients treated at the Orthodontic Clinic of Howard University College of Dentistry was selected. Pretreatment and posttreatment lateral cephalograms were traced on acetate tracing paper: landmarks of the skeletal and soft tissues were identified, and angular and linear measurements were made. Changes in the vertical dimensions of the lips used the Frankfort horizontal as a reference plane and changes in the horizontal dimensions of the lips used the pterygoid plane as a reference plane. Statistical significance was tested by means of two-tailed t tests and Pearson's r correlations. Findings indicated that retraction of the maxillary incisors correlated with an increase in upper lip depth, an increase in interlabial vertical dimension, and an increase in the inferomentolabial angle. The increase in interlabial vertical dimension correlated with an increase in the horizontal dimension of the upper lip relative to upper incisor retraction. This increase in interlabial vertical dimension relative to upper incisor retraction differed significantly from the results of the study by Jacobs1 on a sample of white patients treated with four first-premolar extractions. It is necessary to investigate this difference in future studies using larger sample sizes.

Coagulopathy in hemorrhagic fever with renal syndrome (Korean hemorrhagic fever)

The pathophysiology of bleeding manifestations in hemorrhagic fever with renal syndrome (HFRS) was elucidated by serially evaluating coagulation and fibrinolytic profiles and complement alterations in patients with HFRS. In the early stage of the disease, platelet counts, platelet survival time, and platelet aggregation in vitro decreased. Prolongation of bleeding time, prothrombin time, and activated partial thromboplastin time was noted, with decreases in coagulation factors II, V, VIII, IX, and X. Levels of fibrinogen were decreased, and those of fibrinogen-fibrin degradation products in serum and urine were increased. Concentrations of plasminogen, alpha 2-plasmin inhibitor, and antithrombin III in plasma were depressed. Procoagulant activity was present in plasma. Circulating immune complexes were found, whereas serum levels of C3 were decreased. In the early stage of HFRS, thrombocytopenia, defects in platelet function, and disseminated intravascular coagulation may play central roles in the pathogenesis of bleeding manifestations. Vasculopathy and immunologic aberrations also may play a role.

Demonstration of single chain urokinase-type plasminogen activator on human platelet membrane

Fibrinolytic activity was found to be associated with sonicated platelet membranes after separation from cytosol by differential centrifugation. This fibrinolytic activity was attributed to the presence of a plasminogen activator, which was immunochemically identified as urinary-type plasminogen activator (uPA) by antibody neutralization assay, immunoblotting, and immunofluorescence. The molecular weight (mol wt) of this uPA was 54,000 and was present as the single chain form, although a small amount was detected in a higher mol wt complex indicative of a uPA-inhibitor complex. Treatment of membrane preparations with Triton X-100, 3 mol/L KCl, and 0.1 mol/L glycine, (pH 2.3), but not 10 mmol/L ethylenediamine tetraacetic acid (EDTA), removed the uPA from the membrane. This suggests that uPA is a peripheral membrane protein and that metal ions do not mediate protein-membrane association. Immunofluorescent staining revealed the presence of uPA on the outer surface of the platelet in preparations of intact unstimulated platelets. Thus, uPA is associated with the outer leaflet of the platelet membrane and may be involved with the acceleration of thrombus degradation observed with platelet-rich thrombi.

Refractoriness to platelet transfusion after single-donor consecutive platelet transfusions and its relationship to platelet antibodies

In thirty patients with acute leukemia and severe aplastic anemia receiving random single donor platelet transfusions, the development of refractoriness by consecutive platelet transfusions with cytapheresis and its relationship to the appearance of anti-platelet antibodies were investigated. The median number of platelet transfusions inducing refractoriness was 13 times, and 20% of the patients remained unrefractory despite of the repeated multiple platelet transfusions up to 20 to 25 times. The results of anti-platelet antibody tasts by the enzyme-linked immunosorbent assay(ELISA) and immunofluorescent techniques(IFT) showed no statistically significant relationship with the refractoriness (p greater than 0.1). Although there was significant correlation between the results of ELISA and IFT, both tests were insufficient to find out refractoriness even with the use of pooled platelets from multiple donors as target cells. This study shows that 13 single donor platelet transfusions result in refractoriness, that both ELISA and IFT are insufficient to detect refractoriness despite of their significant correlation, and that other methods than these are needed in order to detect alloimmunization.

Serological identification of thymocyte differentiation antigens

We have examined subfractions of human thymocytes for the expression of novel differentiation antigens. Non-HLA alloantisera procured from multiparous women served as antibody probes. Thymocytes from five individuals were sequentially separated by discontinuous Percoll density gradient centrifugation and a peanut agglutinin (PNA) panning technique. Subfractions were selected and examined for their relative intensity of HLA class I and CD1 antigens as determined by cytofluorometric analysis. Two subfractions were characterized as follows: an immature population (Fr6 PNA-) expressed a high level of CD1 (OKT6 binding) antigen and a low level of class I HLA antigen; and a more mature fraction (Fr3 PNA-) expressed minimal amounts of CD1 antigen and relatively high levels of HLA class I molecules. Fr6 PNA+ and Fr3 PNA- thymocytes were tested for their reactivity with a panel of non-HLA alloantibodies as determined by cytofluorometric analysis. We observed that three alloantibodies demonstrated strong fluorescence staining with Fr6 PNA+ thymocytes only, whereas three other alloantibodies reacted with both the Fr6 PNA+ and the Fr3 PNA- subfractions. All six alloantibodies failed to react with peripheral T cells. However, the six antibodies did react with a panel of cultured T lymphoblastoid leukemic cells and fresh leukemic T cells. Blocking studies demonstrated that these alloantibodies do not bind beta 2-microglobulin-associated determinants. These results suggest that the alloantibodies detect thymocyte differentiation antigens (TDA) that are shared by or are cross-reactive with antigens expressed on certain leukemia T cells. The non-beta 2m-associated TDA antigens are not expressed on normal resting T cells.

Cyclic GMP-phosphodiesterase of rd retina: biosynthesis and content

Deficient cGMP-phosphodiesterase (cGMP-PDE) activity results in elevated levels of cGMP in the rd retina before any pathological signs are observed. Since the enzyme is present in rd retina, although it is barely activated by light, we determined whether its synthesis starts at the same time as that of cGMP-PDE in normal retina, or if either its synthesis is halted or degradation of the enzyme increases before the degeneration of the visual cells. We found that synthesis of cGMP-PDE in rd retina is comparable with that in normal retina while the photoreceptors are viable but that cGMP-PDE content is lower than that of normal retina before the visual cells begin to degenerate. Our results suggest that cGMP-PDE is more susceptible to degradation in rd than in normal photoreceptors or, alternatively, that proteolytic enzyme(s) involved in the degradation of cGMP-PDE are in higher concentration or more active in the defective than in the normal retina.

Modulation of folding pathways of exported proteins by the leader sequence

Leader peptides that function to direct export of proteins through membranes have some common features but exhibit a remarkable sequence diversity. Thus there is some question whether leader peptides exert their function through conventional stereospecific protein-protein interaction. Here it is shown that the leader peptides retarded the folding of precursor maltose-binding protein and ribose-binding protein from Escherichia coli. This kinetic effect may be crucial in allowing precursors to enter the export pathway.

Protein kinase C in the regulation of smooth muscle contraction

The cellular and molecular mechanisms underlying smooth muscle contraction are reviewed in the light of recent studies of smooth muscle ultrastructure and of the role of polyphosphoinositide turnover and protein kinase C function in smooth muscle contraction. A new model of smooth muscle contraction is proposed that differs radically from accepted views, particularly the latch bridge hypothesis, in terms of both Ca2+ messenger function and the molecular events underlying this process. A coordinate fibrillar domain model of contraction is proposed in which the initial and sustained phases of contraction are mediated by different cellular and molecular events. The initial phase of response is mediated by a rise in [Ca2+]c and the resulting calmodulin-dependent activation of both myosin light chain kinase and the dissociation of caldesmon from the actin-caldesmon-tropomyosin-myosin fibrillar domain. These events lead to an interaction between actin and the phosphorylated light chains of myosin just as in previous models. However, this initial phase is followed by a sustained phase in which a rise in [Ca2+]sm stimulates the plasma membrane-associated, Ca2+-sensitive form of protein kinase C that results in the phosphorylation of both structural and regulatory components of the filamin-actin-desmin fibrillar domain. These events underlie the tonic phase of contraction.

Percutaneous endoscopic gastrostomy for enteral nutrition

From January to October, 1986, at Wonkwang University Hospital in Iri, percutaneous endoscopic gastrostomy(PEG) was attempted in 26 patients and was successful in 24. This study was designed to review the technique and to evaluate the efficacy of PEG. The mean operation time was 22 minutes (range: 14 to 42 minutes). After feeding started, early positive nitrogen balance was achieved in all patients. All gastrostomies functioned well throughout the patient’s survival with the longest functioning at 10 month. There were no procedure-related deaths, and morbidity was lower and less severe as compared with large-bore nasogastric tube feeding. Complications included minor wound infection in two patients, stomal growth in one patient, leaks around the tube in two patients, and intraperitoneal leak in one patient. No patient developed aspiration pneumonia or required laparotomy for complications from PEG. The gastrostomy tube was easily removed endoscopically when treatment was completed. Feeding via a large-bore tube increased the risk of aspiration pneumonia (72%) and the feeding cost via a small-bore tube with elemental diet exceeded that of PEG by more than tenfold. This author’s experience with these 26 patients has led to the conclusion that PEG is safe, easy to perform, and effective means of creating feeding gastrostomy without laparotomy or general anesthesia. The authors suggest that PEG be the preferred route of alimentation in those patients who are unable to swallow for prolonged periods of time.

Carbachol-induced protein phosphorylation changes in bovine tracheal smooth muscle

The changes in protein phosphorylation associated with bovine tracheal smooth muscle contraction were studied by labeling intact muscle strips with [32P]PO4(3-) and analyzing the phosphoproteins by two-dimensional gel electrophoresis. Among 20 to 30 phosphoproteins resolvable with the two-dimensional electrophoresis system, the phosphorylation of 12 proteins was reproducibly affected by treatment with carbachol, in a time-dependent manner. Five of these proteins have been identified as 20-kDa myosin light chain, caldesmon, synemin, and two isoelectric variants of desmin. The other 7 are low molecular weight (Mr less than 40,000) cytosolic proteins. One cytosolic protein and myosin light chain are quickly but transiently phosphorylated by carbachol, the peak of myosin light chain phosphorylation being at about 1 min after agonist addition. In contrast, both variants of desmin, synemin, caldesmon, and 5 cytosolic proteins are phosphorylated at varying rates and remain phosphorylated for the duration of carbachol action. These "late" phosphorylation changes occur simultaneously with the dephosphorylation of one cytosolic protein. These carbachol-induced phosphorylation changes, like the contractile response, appear to be calcium-dependent. The addition of 12-deoxyphorbol 13-isobutyrate, a protein kinase C activator, causes a dose-dependent, sustained contraction of tracheal smooth muscle which develops more slowly than that induced by carbachol. This contractile response is associated with the same protein phosphorylation changes as those observed after prolonged carbachol treatment. In contrast, forskolin, an adenylate cyclase activator and a potent smooth muscle relaxant, induces the phosphorylation protein 3 and one variant of desmin. These observations strongly suggest that different phosphoproteins may be mediators of tension development and tension maintenance in agonist-induced contraction of tracheal smooth muscle.

Procoagulant activity and thrombelastography in Korean hemorrhagic fever

Twenty male patients with Korean hemorrhagic fever were evaluated with thrombelastography (TEG) to assess the changes in coagulation system, and the results were compared with those of conventional coagulation tests. Procoagulant activity in the plasma was determined by comparing the reaction time "r" of the normal plasma and that of the mixture of equal parts of the normal plasma and the patient's plasma. The TEG was found to be a useful measure of the changes in the coagulation profile, and provided instant accurate assessment of the patient's hemostatic function. Presence of the procoagulant activity was demonstrated in the plasma of the patients and indicated occurrence of active intravascular coagulation during the early stage of the disease.

Hostility and recovery from melancholia

Twenty inpatients suffering from major depressive illness with melancholia were administered the hostility subscale of the Kellner Symptom Questionnaire and Paykel's Clinical Interview for Depression before and after treatment with amitriptyline. A matched control group of normal subjects had the same assessments at two points in time. Hostility decreased and friendliness increased in depressives after amitriptyline; upon recovery, there were no significant differences in hostility between depressed patients and control subjects, whereas such differences were striking during the illness. Patients who had reported losses before onset of illness rated themselves as more friendly than the other depressives; their hostility did not significantly decrease with recovery. The results suggest that hostility improves with the treatment of depression; life events appear to influence the degree of hostility in depressive illness as well as the response to treatment.