Adenocarcinomas of the prostatic duct in necropsy material

The general consensus about prostatic duct adenocarcinomas is that they have a rather aggressive biological behavior. In addition, studies or reports of latent adenocarcinoma of the prostatic duct in necropsy material are scarce in the literature. We report here three cases of adenocarcinoma of the prostatic duct that were found incidentally among 39 cases of latent acinar prostate adenocarcinomas in necropsy material. We examined the morphologic and histological features of these prostatic duct adenocarcinomas, in order to better understand their biological behavior. We identified two cases of mixed ductal-acinar adenocarcinoma and one case of pure ductal adenocarcinoma. The pure form had a favorable histological differentiation, while the mixed forms had intermediate histological differentiation patterns. Invasiveness was related to both volume and histological differentiation. The finding of prostatic ductal adenocarcinomas among autopsy material, as well as some of their histological features, suggest that these tumors might have a similar biological potential as prostatic acinar cancer.     

Gamma-glutamyl transpeptidase. Elevated activity in myotonic dystrophy.

gamma-Glutamyl transpeptidase, a membrane-bound enzyme playing an important role in the active amino acid transport across cellular membranes, is shown to be elevated in the serum of patients with myotonic muscular dystrophy. No increase of AP, LAP, GOT and GPT activities in the sera of some of the patients studied is observed. Possible interpretations in relation to the pathogenesis of myotonic dystrophy are discussed.     

SCP-containing R20 neurons modulate respiratory pumping in Aplysia

Respiratory pumping in Aplysia consists of transient, synchronous pumping actions of the gill, siphon, mantle shelf, and parapodia. This behavior has previously been shown to be driven by a network of coupled interneurons in the abdominal ganglion, the R25 and the L25 cells. We describe here a pair of electrically coupled cells, the R20 cells, which when active can initiate respiratory pumping or increase its spontaneous rate of occurrence. This action is mediated by a slow, long-lasting excitation of the endogenous burst mechanism of the cells in the R25/L25 network. The R20 cells, which are located in the abdominal ganglion, also make slow inhibitory connections to the RB cells and to the RG cells in that ganglion, and to the gill motoneurons in the branchial ganglion. The R20 cells are immunoreactive to SCPB, a molluscan neuropeptide. Biochemical purification studies demonstrate that each of the R20 cells synthesizes not only SCPB, but also SCPA, a closely related molecule known to be encoded by the same gene as SCPB. The R20 cells also synthesize in abundance several other low-molecular-weight, methionine-containing peptides. The excitatory actions of the R20 cells on the R25/L25 network are mimicked by SCPA and SCPB. However, the inhibitory actions of the R20 cells on the RB cells, the RG cells, and on the cells of the branchial ganglion are not mimicked by the SCPs. Thus, the data support the hypothesis that the R20 cells release SCPA and SCPB and at least one other unidentified transmitter.     

Enzyme activity of G-6-PD, gamma-GT and lysozyme in white cells of schizophrenics

In a controlled study the activity of glucose-6-phosphate dehydrogenase (G-6-PD) in red and white blood cells, gamma-glutamyl transpeptidase (gamma-GT) and lysozyme in serum and white blood cells was studied in 22 drug-free schizophrenic patients and 17 healthy volunteers. The activities of the above enzymes were found to be reduced in the white cells of schizophrenics compared with controls. The differences in activity of G-6-PD in red cells and of gamma-GT and lysozyme in serum between the two groups were not revealed as significant. The observed low enzyme activities might provide a further basis for interpreting the reported functional deficiency in neutrophils of schizophrenics. Possible mechanisms in relation to biological abnormalities in schizophrenia are discussed.