The absence of VGLUT3 predisposes to cocaine abuse by increasing dopamine and glutamate signaling in the nucleus accumbens.

Tonically active cholinergic interneurons (TANs) from the nucleus accumbens (NAc) are centrally involved in reward behavior. TANs express a vesicular glutamate transporter referred to as VGLUT3 and thus use both acetylcholine and glutamate as neurotransmitters. The respective roles of each transmitter in the regulation of reward and addiction are still unknown. In this study, we showed that disruption of the gene that encodes VGLUT3 (Slc17a8) markedly increased cocaine self-administration in mice. Concomitantly, the amount of dopamine (DA) release was strongly augmented in the NAc of VGLUT3(-/-) mice because of a lack of signaling by metabotropic glutamate receptors. Furthermore, dendritic spines and glutamatergic synaptic transmission on medium spiny neurons were increased in the NAc of VGLUT3(-/-) mice. Increased DA and glutamate signaling in the NAc are hallmarks of addiction. Our study shows that TANs use glutamate to reduce DA release and decrease reinforcing properties of cocaine in mice. Interestingly, we also observed an increased frequency of rare variations in SLC17A8 in a cohort of severe drug abusers compared with controls. Our findings identify VGLUT3 as an unexpected regulator of drug abuse.

The role of immunohistochemistry in the diagnosis of hyalinizing clear cell carcinoma of the minor salivary gland: a case report.

A case of hyalinizing clear cell carcinoma (HCCC) of the minor salivary glands of the oral cavity is reported. A 52- year-old woman presented with a growing mass at the base of the tongue. The patient underwent complete resection of the tumour. The histological picture was characterized by trabeculae or solid nests of proliferating cells with a clear cytoplasm, surrounded by a hyalinizing stroma. Tumour cells were immunoreactive for Cytokeratins 5, 6, 7, 8, 14, 17 and 18. No reactivity was observed for cytokeratin 20, vimentin, S- 100 protein, smooth-muscle actin, muscle-specific actin, and calponin. These findings confirmed the diagnosis of HCCC of minor salivary glands of the oral cavity. The clinical presentation, the immunohistochemical pattern and the role of cytokeratins in the differential diagnosis of HCCC are discussed with a review of the literature.

[Late onset Wilson's disease]. / Morbo di Wilson ad esordio tardivo.

BACKGROUND: Wilson's disease (W.D.) is a metabolic disorder that occurs predominantly in children, adolescents, young adults and, rarely, in patients over 35 years. AIMS: In order to verify the prevalence of the clinical presentation of W.D. in adulthood, we analyzed a wide number of clinical presentation of W.D. with particular attention to the age of onset and to the evolutive stage of liver disease at presentation. PATIENTS: Our study is relative to 11 Sardinian adult subjects, aged 36-57 years, 6 males and 5 females, selected from a series of 120 patients affected by W.D. The only criterion utilized to select the patients was their age at presentation, with a cut off of 35 years. METHODS: Liver biopsies were routinely processed and stained with rhodanine, rubeanic acid, orcein and Timm's methods. On the basis of the histological picture, liver biopsies were subdivided into four evolutive stages: stage I = steatosis; stage II = interface hepatitis; stage III = bridging fibrosis; stage IV = cirrhosis. Molecular characterization of W.D. for gene mutations in the Sardinian population was performed in 7 out of 11 cases (-441/-427 del, 5' UTR and 3436 G > A Exon 16). RESULTS: 3 patients showed histological features of the first evolutive stage, 2 of the second, 1 of the third, and 5 of the fourth stage. Histochemistry for copper resulted positive in 9 of 11 cases at least with one of the four employed methods. In the seven patients in whom molecular characterization was perfomed, the gene mutation of W.D. was the same observed more frequently in the Sardinian population (-441/-427 del, 5'UTR). CONCLUSIONS: Our data show that: 1) W.D. with late onset is not rare in Sardinian population; 2) in spite of the late clinical presentation, W.D. may present in the first (3/10) and in the second evolutive stage (2/10) with mild to moderate changes of the liver architecture; 3) patients may show, at presentation, a severe liver disease, characterized by bridging fibrosis or cirrhosis; 4) from a practical point of view, we ask to consider the diagnosis the W.D. in all patients with chronic liver disease of unknown etiology, even if aged over 35 years.

A quick microwave histochemical stain for copper.

A rapid microwave method is described for staining copper in liver. This procedure was compared with a conventional method for copper. To this end, liver sections obtained from patients affected by several liver diseases associated with copper overload, were stained both with the standard rubeanic acid method for copper and with our modification of the same method, incorporating microwave treatment. Liver sections from a normal human newborn were used as a positive control. In Wilson's disease in the cirrhotic stage, copper was detected by the conventional method solely in periportal cells; following the microwave treatment, we were able to demonstrate copper in the whole lobule. In alcoholic cirrhosis, rubeanic acid stained copper only in a few periportal cells, while, by our modified method, copper was detected in almost all periportal hepatocytes. In chronic biliary tract disease, and in the newborn liver, copper was demonstrated in a few periportal cells by both the two histochemical procedures. In conclusion, although copper was detected by both procedures, a different degree of positivity was sometimes observed by using microwaves. Moreover, the microwave-treated sections showed more contrast and less artifacts. From a practical point of view, for the simplicity of employment and, above all, for its quickness (10 min), we suggest the use of our method in all conditions where copper overload is suspected.

Value of histochemical stains for copper in the diagnosis of Wilson's disease.

AIMS: The histochemical demonstration of hepatic copper is important in the diagnosis of Wilson's disease (WD). Conflicting results have been published with regard to the ability of different histochemical methods to demonstrate copper storage in the liver. Therefore, we evaluated the diagnostic value of three available histochemical methods in a large series of patients affected by WD. METHODS AND RESULTS: Seventy-nine consecutive liver needle biopsies, from 74 patients, 39 males and 35 females, aged 4-60 years (mean age 28.5 years) were stained with orcein, rhodanine and using Timm's method. On the basis of the histological picture, liver biopsies were subdivided into three groups: group A, steatosis; group B, interface hepatitis; group C, chronic hepatitis with bridging fibrosis and/or cirrhosis. In group A, 30.4% of the cases were positive using Timm's method, vs 13.2% using the rhodanine and 17.5% using the orcein method. In group B, Timm's method was positive in 40.1% while rhodanine and orcein showed positivity in 26.7%. In group C, the Timm's method stained 58.6%, rhodanine 36.6% and orcein 29.3% positively. CONCLUSIONS: Our data show that: (1) Timm's silver stain is the most sensitive method for the demonstration of copper in all cases of WD; (2) rhodanine and orcein have minor value in the diagnosis of WD, especially in the early stages of the disease; (3) to increase the diagnostic value of histochemistry for copper multiple histochemical stains in serial sections are required; and (4) although hepatic copper concentration is highest in the early stages of WD, the histochemical demonstration fails in a large number of cases.

[Multiple histochemical methods in the diagnosis of Wilson's disease. (Presentation of 74 cases and review of the literature)]. / Ruolo dello studio istochimico multimetodico nella diagnosi di morbo di Wilson (presentazione di 74 casi e revisione della letteratura).

Conflicting results have been reported on the usefulness of histochemistry for copper in the diagnosis of Wilson's Disease (W.D.). In spite of the high number of methods proposed in the literature, no-one has shown to have the characteristics typical of a good histochemical method: high sensitivity associated with high specificity. On this basis, it seemed of interest to evaluate, in a large series of patients with W.D., the diagnostic value of the most commonly used histochemical methods for copper (rhodanine, orcein and Timm's method). To this end, 74 liver needle biopsies from patients affected by W.D., 39 males and 35 females, aged 4-60 years (mean age 28.5 years), were stained with rhodanine (R), orcein (O) and Timm's (T) methods. On the basis of the histological picture, liver biopsies were subdivided in four evolutive stages: stage I = steatosis; stage II = interface hepatitis; stage III = bridging fibrosis; stage IV = cirrhosis. In stage I, histochemistry for copper was positive in 11 out of 21 cases: 6 cases were T+; 1 case R+ and 2 cases O+; 2 cases were T+, R+, O+. In stage II, 11 out of 14 cases were positive for copper staining: 4 T+, 2 R+ and 2 O+; 3 cases were contemporary positives for T, R, O. In stage III, 22 out of 25 cases resulted positive: 8 T+, 3 R+ and 1 O+; 10 cases were positives, in the mean time, for more of one method. In stage IV, 12 of 14 cases were positives: 5 T+, 2 R+, 2 O+ and 3 cases were contemporaneously positives for multiple methods. Our data show that: 1) the percentage of positivity obtained using three histochemical methods for copper is higher than using only one method. From a practical point of view, it is mandatory to utilize, in clinical practice, multiple histochemical stains in order to increase the diagnostic utility of histochemistry for copper; 2) the Timm's method appears to be the most sensitive method for the demonstration of copper in all stages of W.D.; 3) even though hepatic copper already abounds in the early stages of W.D., this pool of intrahepatic copper is not yet demonstrable with any of the three histochemical techniques utilized.