Toward a biochemical classification of depressive disorders. I. Differences in urinary excretion of MHPG and other catecholamine metabolites in clinically defined subtypes of depressions.

The urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) and other catecholamine metabolites was measured in a series of 63 patients with various clinically defined subtypes of depressive disorders. MHPG excretion was significantly lower in patients with bipolar manic-depressive depressions and schizo-affective depressions than in patients with unipolar nonendogenous depressions. Patients with schizophrenia-related depressions also excreted reduced levels of MHPG when compared with patients with unipolar nonendogenous depressions. Moreover, levels of urinary epinephrine and metanephrine were significantly lower in patients with schizophrenia-related depressions. These data, coupled with our recent finding that patients with schizophrenia-related depressions had significantly higher levels of platelet monoamine oxidase activity than control subjects of patients with unipolar endogenous depressions, suggest that we can discriminate three biochemically discrete subgroups of depressive disorders corresponding to the following clinically defined subtypes: (1) the bipolar manic-depressive depressions plus the schizo-affective depressions; (2) the unipolar nonendogenous depressions; and (3) the schizophrenia-related depressions.

Toward a biochemical classification of depressive disorders. II. Application of multivariate discriminant function analysis to data on urinary catecholamines and metabolites.

The previous article in this series reported on the differences in urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) in patients with various clinically defined subtypes of depressive disorders. We now report that further biochemical discrimination among depressive subtypes is provided by the following equation, derived empirically by applying multivariate discriminant function analysis to data on urinary catecholamine metabolits: Depression-type (D-type) score = C1(MHPG) + C2(VMA) + C3(NE) +C4(NMN + MN)/VMA + C0. In the original derivation of this equation, low scores were related to bipolar manic-depressive depressions, and high scores were related to unipolar nonendogenous (chronic characterological) depressions. Findings from a series of depressed patients whose biochemical data had not been used to derive this equation confirmed these differences in D-type scores among subtypes of depressions. The findings presented in this report further suggest that we can discriminate three biochemically discrete subgroups of depressive disorders.

Toward a biochemical classification of depressive disorders. III: Pretreatment urinary MHPG levels as predictors of response to treatment with maprotiline.

Pretreatment urinary MHPG levels were examined in 28 depressed patients as a possible predictor of response to treatment with maprotiline, a tetracyclic antidepressant that exerts potent effects on norepinephrine uptake, but has little effect on serotonin uptake. Maprotiline was administered in doses up to 150 mg/day during the first 2 weeks after which time the dose could be increased incrementally up to 300 mg/day if indicated clinically. At 2 weeks, patients with low pretreatment urinary MHPG levels responded more favorably to treatment than did patients with high MHPG levels. At 4 weeks, patients with low MHPG levels continued to show more favorable responses; however, differences between the two groups were less clear-cut than at 2 weeks. The findings suggest the patients with low pretreatment urinary MHPG levels are more sensitive to, and respond more rapidly to, treatment with maprotiline than patients with high pretreatment urinary MHPG levels.

Morphological comparison of meloidogyne males by scanning electron microscopy.

Field plots of Tifton loamy sand were treated with methyl bromide, DD-MENCS, or ethoprop for control of root-knot nematodes, Meloidogyne incognita, in a multiple cropping system of turnips, field corn, and southern peas. Annual applications of methyl bromide and DD-MENCS in November or December suppressed nematode numbers to very low levels through September, but numbers increased in the following October, November, and/or December. No benefit was found from ethoprop applied to DD-MENCS-treated plots before the planting of each crop. Nematode numbers were not significantly suppressed by ethoprop alone. Concentrations of ethoprop in the 0-15-cm soil layer were near 6 mug/g at application but were < 1mug/g of soil 5 days later on corn and southern peas and 30 days later on turnips. Ethoprop concentrations of 4.6 to 5.6 mug/g of soil are too low for adequate control of root-knot nematodes on field corn and southern peas in multiple cropping systems. Stepwise regression analyses indicated that 81% and 36% of the variations in concentration of ethoprop in the soil were attributable to the amount of water that the plots received when the maximum soil temperature ranged from 10 C to 19 C and from 31 C to 41 C, respectively, and that 11% was attributable to the maximum soil temperature within the temperature range of 17 C to 33 C.

Dispersion, Dissipation, and Efficacy of Methyl Bromide-Chloropicrin Gas vs. Gel Formulations on Nematodes and Weeds in Tifton Sandy Loam.

Dispersion, dissipation, and efficacy of gas and gel formulations of methyl bromidechloropicrin (202, 269, 336, and 403 kg/ha) on nematodes and weeds on tomato were studied in field plots. Concentrations of methyl bromide and chloropicrin 4 hr after soil treatment were greater at a depth of 15 cm than at 30, 45, or 60 cm. The concentrations of both chemicals decreased with lower doses, greater depths, and longer times after application. The gel formulation was more persistent than the gas formulation at both 336 and 403 kg/ha at depths of 30 and 45 cm, especially 24 and 36 hr after chemical application. Plant growth and yield were improved when nematodes and weeds were controlled.

Influence of water and soil temperature on the concentration and efficacy of phenamiphos for control of root-knot nematodes.

Field plots of Tifton loamy sand were treated with phenamiphos for control of root-knot nematodes in a multiple-crop system of turnips, field corn, and southern peas. Preplant applications of phenamiphos protected roots of turnips and corn from damage by root-knot nematodes. Concentrations of phenamiphos at application in the 0-15-cm soil layer were near 6 mug/g on turnips and near 4 mug/g on corn and southern peas. After 30 d, concentrations were approximately 1 mug phenamiphos/g of soil for all crops. Concentrations of 2.0-3.8 mug phenamiphos/g of soil for 9-d duration appeared to be adequate for control of root-knot nematodes on field corn and southern peas in this multiple-crop system. Stepwise regression analyses indicated that 31%, 62%, and 22% of the variations in concentration of phenamiphos in the soil planted to turnips, corn, and southern peas, respectively, were attributable to the amount of water that the plots received. Soil temperature had no effect on concentrations of phenamiphos.