Bilateral parotid sialolithiasis in a patient with acquired immunodeficiency syndrome and immunoglobulin G multiple myeloma

Bilateral multiple parotid calculi, which are uncommonly diagnosed in the normal population, have never been reported in patients infected with human immunodeficiency virus. Herein we report a case of bilateral parotid sialolithiasis in a patient who had acquired immunodeficiency syndrome and was affected by multiple myeloma. The possible etiopathogenesis in view of the alterations of immunity, oral pH, and salivary composition that are observed in multiple myeloma and in human immunodeficiency virus infection are discussed.

Synthesis and biological evaluation of a series of quinazoline-2-carboxylic acids and quinazoline-2,4-diones as glycine-NMDA antagonists: a pharmacophore model based approach

The synthesis and glycine-NMDA binding activity of a series of quinazoline-2-carboxylic acids 1 and quinazoline-2,4-diones 2, containing all the essential and optional pharmacophoric descriptors required by a putative glycine antagonist model, are reported. The binding results show that only three of the title compounds displayed micromolar receptor affinity, demonstrating how disappointing the synthesis of receptor ligands based only on interaction models can be.

[Medical-legal evaluation of laryngeal dysfunction to determine disability]

The "New Table indicating the percentage of disability resulting from injury and disabling diseases" approved by the Italian Ministerial Decree dated February 5, 1992 gives a superficial, highly disorganized handling of laryngeal pathologies. This Table only considers phonatory function disorders which are included in a special section; it totally neglects dyspnea and dysphagia of laryngeal origin. This omission cannot even be overcome on the basis of similarities since there are no analogous items listed for reference. In fact, the parameters applied to evaluate dyspnea (CV, VEMS, O2 consumption) apply to ventilation disorders of a pulmonary nature and cannot, therefore, be used in cases of laryngeal dyspnea. Moreover, the Table does not deal with dysphagia at all. In addition, the basis for the Table--the concept of permanent functional damage--is not always adhered to in giving indications for evaluation of phonatory tract damage. The purpose of the present work is not, however, to propose a different way to determine the percentages for the individual items in the tables; rather, the aim is to suggest a different, highly standardized procedure for evaluating laryngeal dysfunctions which is easy to apply.

Andrological study of two young identical twin bulls

A study was conducted on two young Italian Holstein bulls obtained by embryonic splitting and, therefore, genetically identical. The andrological evaluation of the subjects revealed a significant difference in semen freezability, valued according to forward motility after thawing (57.34 vs. 46.92; P < 0.01). There was, however, no difference in the quality of fresh semen.

Interleukin-10 down-regulates oxidative metabolism and antibody-dependent cellular cytotoxicity of human neutrophils

The authors investigated the ability of interleukin-10 (IL-10) to modulate some constitutive or interferon-gamma (IFN-gamma)-enhanced activities of human neutrophils. An 18h culture of neutrophils with IL-10 dose-dependently down-regulated their capacity to produce O(2)- and lucigenin-amplified chemiluminescence in response to n-formyl-methionyl-leucylphenyl-alanine (FMLP). Furthermore, treatment of neutrophils with IL-10 decreased in a dose-dependent fashion, their capacity to lyse antibody-coated sheep erythrocytes. Membrane expression of Fc gamma RI, Fc gamma RII, Fc gamma RIII, CR1, CR3 and Fc gamma R- and CR-mediated phagocytosis were not modified by the cytokine. Culture of neutrophils with IFN-gamma (100 U/ml) did not modify their Fc gamma R- and CR-mediated phagocytosis, but significantly up-regulated Fc gamma RI and CR3 membrane expression as well as their oxidative metabolism and antibody-dependent cellular cytotoxicity (ADCC). When IL-10 and IFN-gamma were added simultaneously to neutrophil culture, IL-10 dose-dependently reduced IFN-gamma-induced increase of CR3 expression, O(2)- production (in response to both FMLP and phorbol 12-myristate 13-acetate, or PMA) and ADCC, but did not change Fc gamma RI expression on phagocytes. These results demonstrate that IL-10 is a significant neutrophil deactivator and provide new information on the role of IL-10 in the regulation of neutrophil-mediated inflammatory processes.

Tricyclic heteroaromatic systems. 3-substituted 1,2,3,5,6,7-hexahydro-2,5,6-trioxopyrazino[1,2,3-de]-quinoxalines as novel antagonists at the glycine-NMDA site

Two novel antagonists of the glycine-NMDA receptor have been synthesized and tested for their ability to displace [3H]glycine from its specific binding site in rat brain cortical membranes. The 3-substituted pyrazino[1,2,3-de]quinoxalin-2,5,6-triones 1a-b contain all the essential pharmacophoric descriptors of a glycine receptor antagonist. A model is proposed for the binding of these compounds that includes some of the interactions postulated for the potent glycine-NMDA receptor antagonist L-689,560.

[Ultrasonic diagnosis of De Quervain's stenosing tenosynovitis]

This study was aimed at stressing the role of US of the first dorsal compartment of the wrist as the initial diagnostic approach in the study of De Quervain's syndrome, thanks to the high diagnostic yield of this technique. We report on 14 cases of De Quervain's stenosing tenosynovitis whose onset of the symptoms ranged 3-24 months before the US exam. The patients were subdivided into three groups, according to disease stage and US patterns; 5 patients were in group 1, six in group 2 and 3 in group 3. The most frequent US findings were: thickening of the tendons, which appeared as separate structures or as a single structure (pseudofusion); diffuse or, in most cases, focal thickening of the sheaths; changes in tendon echogenicity; impaired tendon sliding, which was reduced or absent due to fibrous adhesions and compression by the sheaths. Diffuse tendon and sheath thickening was prevalent in group 1, where the onset of symptoms ranged 3-10 months earlier. Focal sheath thickening and tendon pseudofusion were prevalent in group 2, where the onset of symptoms ranged 8-15 months earlier. Tendon degeneration and fibrous adhesions between tendons and sheaths, as well as the US changes observed in group 2, were found in group 3 where the onset of symptoms ranged 18-24 months earlier. These US changes were not influenced by medical therapy, with the exception of local injections of corticosteroids. To conclude, we propose a classification of De Quervain's syndrome into three stages, according to the US signs characterizing the different stages of disease evolution and the time of onset of the symptoms.

Neutrophil-derived superoxide anion induces lipid peroxidation and stimulates collagen synthesis in human hepatic stellate cells: role of nitric oxide

Experimental evidence indicates that the lipid peroxidation of biological membranes is often associated with the development of liver fibrosis. We have studied the effect of neutrophil-derived reactive oxygen species (ROS) on collagen synthesis by human hepatic stellate cells (HSC), the major source of collagen in the liver, in a coculture system. Lipid peroxidation in the cocultures was evaluated in terms of either malondialdehyde (MDA) production or the formation of MDA/4-hydroxynonenal protein adducts. The expression of cellular messenger RNAs (mRNAs) was evaluated by either Northern blotting or RNAse protection assay. Nitric oxide (NO) synthase activity in cells was measured by [3H]citrulline formation from [3H]arginine. In vitro exposure of HSC to ROS resulted in the early induction of lipid peroxidation and was associated with a marked increase (threefold) of procollagen I mRNA expression and synthesis. The addition of antioxidants, such as vitamin E or superoxide dismutase (SOD), impaired this stimulation. The inhibition of neutrophil NO formation by N(G)-monomethyl-L-arginine made the ROS-induced stimulation of procollagen I more evident. The addition of xanthine/xanthine oxidase X/XO, a superoxide anion donor, to HSC cultures strongly increased procollagen I synthesis. This stimulation was hampered by the addition of both SOD and sodium nitroprusside (an NO donor). The contribution of HSC to the production of NO in our coculture system was negligible, because inducible NO synthase (iNOS) mRNA was almost undetectable in these cells, and also because the amount of NO produced by HSC stimulated with tumor necrosis factor alpha (TNF-alpha) and lipopolysaccharide (LPS) was 500 times less than that synthesized by neutrophils. In conclusion, these results indicate that neutrophil-derived ROS may contribute to the development of hepatic fibrosis associated with alcoholic hepatitis. NO produced by neutrophils may exert a "protective" antioxidant effect by operating as a scavenger of superoxide anion.

Neurotoxicity and ototoxicity of cisplatin plus paclitaxel in comparison to cisplatin plus cyclophosphamide in patients with epithelial ovarian cancer

PURPOSE

To compare the neurotoxicity and ototoxicity of combination cisplatin plus paclitaxel versus cisplatin plus cyclophosphamide using extensive clinical and instrumental evaluation.

PATIENTS AND METHODS

Forty-six of 51 consecutive patients affected by-epithelial ovarian cancer seen in our institution between October 1994 and August 1995 entered the study. After randomization, they were assigned to receive cisplatin 75 mg/m2 every 3 weeks associated with cyclophosphamide 750 mg/m2 (CC group, n = 22) or paclitaxel 175 mg/m2 over a 3-hour infusion (CP group, n = 24). Treatment was repeated six times in 43 patients and nine times in 25. Before treatment and after three, six, and nine courses of chemotherapy, patients underwent clinical and instrumental neurologic and otologic examinations.

RESULTS

Mild sensory impairment was evident even after only three courses of both treatments and signs and symptoms were more severe at the end of treatment. On clinical grounds only, it was possible to demonstrate after six and nine courses a difference between CC and CP treatment, due to the involvement in some CP patients of pain and thermal sensory modalities. However, the overall severity of the neuropathy was similar. Audiometric parameters demonstrated a more negative outcome after treatment in CC compared with CP patients. However, the different severity of the involvement was closely correlated to this initial difference in audiologic performance.

CONCLUSION

Up to nine courses of chemotherapy, the CC and CP schedules are similar in terms of severity of neurotoxicity and ototoxicity when patients are evaluated during and immediately after treatment. With the doses used in our study, these toxicities are not dose-limiting. Our results suggest that most of the toxic effects observed during the treatment were due to cisplatin.

Protein kinase C activation regulates human serotonin transporters in HEK-293 cells via altered cell surface expression

Antidepressant- and cocaine-sensitive serotonin (5-hydroxytryptamine, 5-HT) transporters (SERTs) dictate clearance of extracellular 5-HT after release. To explore protein kinase C-mediated SERT regulation, we generated a stable human SERT (hSERT)-expressing cell line (293-hSERT) and evaluated modulation of 5-HT activity via studies of 5-HT flux, hSERT-mediated currents under voltage clamp, and surface distribution of SERT protein. 293-hSERT cells exhibit saturable, high-affinity, and antidepressant-sensitive 5-HT uptake as well as hSERT-dependent whole-cell currents. In these cells, the protein kinase C activator beta-PMA caused a time-dependent reduction in 5-HT uptake capacity (Vmax) after acute application and a reduction in SERT-mediated currents. Effects of beta-PMA were mimicked by the phorbol ester beta-PDBu, were not observed with the inactive alpha-isomers, and could be blocked by treatment of cells with the protein kinase C inhibitor staurosporine. Biotinylation/immunoblot analyses showed that activity reductions are paralleled by a staurosporine-sensitive loss of surface SERT protein. These data indicate that altered surface abundance, rather than reduced catalytic transport efficiency, mediates acute PKC-dependent modulation of 5-HT uptake.

Structure-activity relationship studies of novel pyrazolo[1,5-c][1,3]benzoxazines: synthesis and benzodiazepine receptor affinity

Some 2-arylpyrazolo[1,5-c][1,3]benzoxazin-5-ones 1 and 5- oxopyrazolo[1,5-c][1,3]benzoxazin-2-carboxylates 2 were prepared and biologically evaluated for their binding at benzodiazepine receptor (BZR) in rat cortical membranes. Structure-activity relationship studies suggest that, although proton donor d and proton acceptor a1 are both optional pharmacophoric descriptors, at least one of them must be present for good BZR affinity. When the proton donor d is not present, the heteroatom acceptor a1 is necessary either in the tricyclic core or in the appended substituent at the C-2 to obtain sub-micromolar BZR affinity.

Reversible inhibition of cholinesterases by opioids: possible pharmacological consequences

The inhibitory potency of opioids belonging to different structural categories on electric eel and rat brain acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BuChE) was investigated. The phenylazepine meptazinol, the pyrrolo-[2,3-b]-indole derivative eseroline and the benzomorphan normetazocine were the most potent inhibitors of AChE among the compounds tested. These were followed by (-)-metazocine, N-allylnorcyclazocine, 3-(1,3-dimethyl-3-pyrrodinyl)-phenol, levallorphan, levorphanol and pentazocine. The opioids which inhibited horse serum BuChE were in order of potency: meptazinol, methadone, profadol, levallorphan and 1,2,3-trimethyl-3-(3-hydroxyphenyl)-piperidine. The results of this work appear consistent with the fact that the anticholinesterase activity of the opioids is not confined to specific structural categories, although conformationally constrained molecules, like those of morphinans, benzomorphans or pyrrolo-[2,3-b]-indoles, appear to favour affinity for AChE, whereas highly flexible molecules, like those of acyclic opioids, inhibit BuChE in a rather selective way. In all cases, the inhibitory action of opioids markedly differed from that of carbamates or organophosphorous compounds, in that it was time-independent and immediately reversible on dilution. In general the anticholinesterase action of opioids does not seem to influence appreciably the pharmacological properties of the drugs since it is evidenced at drug doses higher than those which are analgesic. However, in the case of mixed agonist/antagonist opioids with rather weak analgesic activity, the enzyme inhibition caused by the levels of circulating drugs can be so marked as to exert also a cholinergic component of action.

Immunomodulatory effects of occupational exposure to mancozeb

The effects of occupational exposure to ethylene-bis-dithiocarbamate of manganese and zinc on the immune system were evaluated in a group of mancozeb-exposed manufacturers and controls. The immune system tests revealed the following: (a) lymphocyte proliferative responses triggered by different activators and mitogen-induced IL-2 production were higher in exposed subjects than in controls; (b) production of monocyte/macrophage-derived IL-1 and polyclonal IgG and IgM, by beta-lymphocytes, did not differ between exposed subjects and controls; (c) percentages and absolute numbers of total T-cells, T-helper cells, T-suppressor/cytotoxic cells, activated T-cells, total beta-cells, and natural killer cells were similar in exposed subjects and controls; (d) serum immunoglobulin classes and complement fractions were within the range of normality; and (e) rheumatoid factor and non-organ-specific serum autoantibodies were absent in exposed and control subjects. An increase in T-cell functional response was found in the exposed group, suggesting a slight immunomodulator effect of mancozeb in conditions of low-level, prolonged occupational exposure.

Effects of Salmonella assay negative and positive carcinogens on intrachromosomal recombination in G1-arrested yeast cells

A wide variety of carcinogens including Ames assay (Salmonella) positive as well as Salmonella-negative carcinogens induce intrachromosomal recombination (DEL recombination) in strain RS112 of Saccharomyces cerevisiae. It has been previously shown that the Salmonella-positive carcinogens ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS) and 4-nitroquinoline-N-oxide (4-NQO) and the Salmonella-negative carcinogens safrole, benzene, thiourea, carbon tetrachloride and urethane induce DEL recombination in G2-arrested yeast cells. DEL recombination is preferentially induced by safrole, benzene and carbon tetrachloride in G2-arrested cells which might be explained by preferential induction of unequal sister chromatid recombination leading to deletions. To test this, cells of strain RS112 were arrested in the G1 phase of the cell cycle, exposed to these carcinogens and the frequencies of DEL and interchromosomal recombination (ICR) were determined. EMS, MMS and 4-NQO induced DEL recombination and ICR in G1-arrested cells with a linear dose-response curve. In contrast, the Salmonella-negative carcinogens safrole, benzene, carbon tetrachloride, thiourea and urethane induced DEL recombination and ICR with a threshold below which no significant increase was seen and only at already cytotoxic doses. EMS, MMS and 4-NQO were more recombinagenic in previous experiments with growing cells than in G1-arrested cells. On the other hand, safrole, benzene and carbon tetrachloride were more recombinagenic in G1-arrested than in growing cells. Thus, inducibility of DEL recombination in G1-arrested cells parallels inducibility in G2-arrested cells making it less likely that sister chromatid recombination events might be involved. These data are discussed in terms of the mechanism of induced DEL recombination and the possible biological activities of these carcinogens.

Norepinephrine transporters have channel modes of conduction

Neurotransmitter transporters couple to existing ion gradients to achieve reuptake of transmitter into presynaptic terminals. For coupled cotransport, substrates and ions cross the membrane in fixed stoichiometry. This is in contrast to ion channels, which carry an arbitrary number of ions depending on the channel open time. Members of the gamma-aminobutyric acid transporter gene family presumably function with fixed stoichiometry in which a set number of ions cotransport with one transmitter molecule. Here we report channel-like events from a presumably fixed stoichiometry [norepinephrine (NE)+, Na+, and Cl-], human NE (hNET) in the gamma-aminobutyric acid transporter gene family. These events are stimulated by NE and by guanethidine, an hNET substrate, and they are blocked by cocaine and the antidepressant desipramine. Voltage-clamp data combined with NE uptake data from these same cells indicate that hNETs have two functional modes of conduction: a classical transporter mode (T-mode) and a novel channel mode (C-mode). Both T-mode and C-mode are gated by the same substrates and antagonized by the same blockers. T-mode is putatively electrogenic because the transmitter and cotransported ions sum to one net charge. However, C-mode carries virtually all of the transmitter-induced current, even though it occurs with low probability. This is because each C-mode opening transports hundreds of charges per event. The existence of a channel mode of conduction in a previously established fixed-stoichiometry transporter suggests the appearance of an aqueous pore through the transporter protein during the transport cycle and may have significance for transporter regulation.

Flow cytometric analysis of bronchoalveolar lavage and venous blood lymphocyte phenotype for the diagnosis of acute graft rejection in lung transplant patients. The Lung Transplant Group, Ospedale Maggiore di Milano

OBJECTIVE

To investigate modifications of phenotype in bronchoalveolar lavage (BAL) and venous blood lymphocytes as markers of acute organ rejection in lung transplant patients.

STUDY DESIGN

Five consecutive patients receiving successful single lung transplants between March 1991 and April 1992 were followed for two years; serial bronchoscopies with BAL and transbronchial biopsies (TBBs) were performed. BAL and venous blood lymphocyte cytofluorimetry was performed at every procedure, and an index, (blood T4/T8)/(BAL T4/T8), was computed.

RESULTS

The index was always > or = 3 in the two patients who did not have graft rejection and always < 3 in the two patients who had repeated episodes of acute rejection (even when no rejection was apparent). The index was frequently < 3 when cytomegalovirus infection was diagnosed.

CONCLUSIONS

Since BAL is far less invasive and carries lower risks than TBB, the index might be considered, if our results are confirmed, for screening patients at high risk of acute rejection. TBB could be used as a confirmatory tool for patients who have an index < 3.

Combined craniofacial approach to facial tumours involving the anterior skull base

The authors report their experience on six male patients and one female patient (age range: 58-76 years, median: 67) with facial tumours involving the anterior skull base, undergoing craniofacial resection between January 1992 and May 1994 at the Division of Surgical Oncology in the Tumor Institute, Genoa. Three patients had squamous carcinoma and adenocarcinoma of the nasal fossa; two patients had squamous carcinoma rT4NO and adenocarcinoma rT4NO1 of the maxillary sinus; one patient had squamous carcinoma of the eyelid, and another had squamous carcinoma of the internal chantus. Four patients had had previous radiotherapy, another underwent pre-operative chemoradiotherapy, and only two patients had not been treated before. A proper craniofacial tumour resection was performed in three patients; one patient had a left maxillectomy with ethmoidectomy and orbital exenteration; one patient underwent maxillectomy, resection of the medial and inferior wall of the orbit, ethmoidectomy, and orbital exenteration; one patient underwent maxillectomy, ethmoidectomy, and mucosectomy of the sphenoidal sinus, and one patient had total ethmoidectomy. As for reconstruction procedures of the anterior skull base, lyophilized dura with galeal pericranial flap was commonly used. A myocutaneous flap transposition (transverse rectus abdominis and latissimus dorsi myocutaneous flap) was used in two patients for the reconstruction of the resected tissues and bones of maxillary and orbital regions. Post-operative complications included intraoperative liquorrhea in one patient; one case of early and serious pneumocephalus; flap necrosis occurred following transposition of latissimus dorsi. Median hospital stay was 34 days. After a median follow-up of 18 months (range: 3 to 34 months) five of seven patients (71.4%) are alive and disease-free at 15, 17, 18, 30 and 34 months from surgery.

Synthesis and binding activity of some pyrazolo[1,5-c]quinazolines as tools to verify an optional binding site of a benzodiazepine receptor ligand

The synthesis and binding activity at the benzodiazepine receptor of some 2-substituted pyrazolo[1,5-c]quinazolines are reported. The structure-activity relationships and in vitro efficacy of the title compounds, which are devoid of the proton acceptor atom at position 1, are similar to those of some previously reported tricyclic heteroaromatic compounds. This suggests that a proton acceptor at position 1 is an optional binding site of a benzodiazepine receptor ligand which only affects potency.

Hydroxyurea induces recombination in dividing but not in G1 or G2 cell cycle arrested yeast cells

Hydroxyurea, a chemotherapeutic and radiosensitizing agent, inhibits ribonucleotide reductase, arrests cells in the S-phase and is mutagenic and recombinagenic. In this paper we investigated whether the recombinagenic activity of hydroxyurea is due to the same activity that leads to arrest in the S-phase or to a more direct action on DNA. The effect of hydroxyurea on intrachromosomal and interchromosomal recombination was investigated in dividing and in G1 or G2 cell cycle-arrested cells of the yeast Saccharomyces cerevisiae. Treatment of dividing cells with hydroxyurea resulted in a large increase in recombination frequencies, even at low non-toxic doses. In contrast, in cells arrested in the G1 or G2 phase, hydroxyurea failed to induce recombination, even at 60-fold higher toxic doses. The presence of metabolic activation (S9 mix) did not change the effects of hydroxyurea on recombination. The data suggest that the recombinagenic activity of hydroxyurea may not be due to any direct effect of hydroxyurea on DNA, but may be linked to the inhibition of ribonucleotide reductase causing inhibition of DNA synthesis leading to S-phase arrest and possibly causing recombinagenic lesions.

Functional role of low-voltage-activated dihydropyridine-sensitive Ca channels during the action potential in adult rat sensory neurones

Neuronal cell firing is crucial to nerve-nerve communication. The ability to produce consecutive action potentials is related to the activation of inward currents after each upstroke. If fast Na current is indeed responsible for the overshoot, it is still unclear which current drives membrane voltage to the Na threshold. In this study we present evidence that in adult rat sensory neurones a dihydropyridine-sensitive Ca channel exists in addition to the well characterized L-type, or high-threshold Ca channel. During stimulated action potential trains, L-type Ca channels open during the excitation wave, whereas activity of the other dihydropyridine-sensitive Ca channel was observed primarily between action potentials. This second Ca pathway shows remarkably long openings at negative potentials after a series of positive prepulses. The nerve action potential and the repetitive firing work as a physiological Ca channel facilitation mechanism. Therefore, we suggest that this novel Ca conductance provides inward current, between two consecutive action potentials, able to modulate the frequency of neuronal bursts.

Acetylcholinesterase inhibition and protection by dizocilpine (MK-801) enantiomers

The optical isomers of the N-methyl-D-aspartate (NMDA) receptor ion-channel blocker dizocilpine (MK-801) were shown to interact with electric eel and rat brain acetylcholinesterase (AChE) in a mixed competitive-noncompetitive way. The (-) form, pharmacologically less active, was the most potent of the two isomers as an AChE inhibitor (Ki for electric eel and rat brain AChE being 6.2 and 17.9 microM, respectively, compared with 200 and 450 microM, respectively, of the (+) form). Both enantiomers premixed with AChE preparations, dose-dependently protected the enzyme from inactivation by diisopropylfluorophosphate (DFP). The maximal protective effects against 40 and 10 microM DFP were in the ranges 10.7-23.8 and 19.5-31.4% of control enzymic activity for the (+) and (-) forms of dizocilpine, respectively. The extent of the protective effect against DFP was increased up to 80.1% of control enzymic activity for (-)-dizocilpine and to 38.4% for (+)-dizocilpine by diluting the enzymic mixtures 1000 times after treatment with the organophosphate agent. The two enantiomers added to AChE 15 min after DFP, failed to reactivate the enzyme. Finally, it was shown that (+)- and (-)-dizocilpine dose-dependently and competitively decreased the DFP bimolecular reaction constant, K(i). We conclude that dizocilpine exerts a protective action towards AChE against irreversible DFP inhibition, but the molecular mechanism of such an action is at present unclear.