Management of traumatic parotid sialoceles and fistulae: a prospective study

A prospective study of 13 patients with traumatic parotid fistulae or sialoceles showed that 54% resolved on conservative management within a 3 week period. Those that did not were treated by internal surgical drainage with uniform success, although care had to be taken with the catheter placement. No factors predictive of those cases requiring operative drainage other than failure of conservative management were found.

Administration of sucralfate prolongs survival of animals with experimental peptic ulceration

Ligation of the pig bile duct (BDL) results in 100% incidence of pars esophageal ulceration within 48 hours of the procedure. Usually such ulceration is uniformly fatal unless a highly selective vagotomy is performed simultaneously with the BDL. The administration of sucralfate to pigs with BDL prolonged their survival for up to 7 days, with evidence of healing of the ulcer on macroscopic and histologic observations. An increase in cell proliferation in the squamous epithelium of the ulcerated area was also seen in this sucralfate group. These features were not seen in controls, pigs with BDL only, or pigs with BDL and with magaldrate (Riopone), colloidal bismuth subcitrate (DeNol), or carbenoxolone. Analysis by Sepharose 2B gel filtration showed that there was no significant difference in the amounts of polymeric mucin in any group, with a wide scatter of the data seen especially for pigs in the untreated BDL-only group. This study suggests that sucralfate may enhance healing in this experimental pig ulcer model via a mechanism independent of the stimulation of mucus secretion. We propose that coating the mucosa with sucralfate provides a temporary substitute barrier that creates a microenvironment conducive to wound repair by mucosal proliferation.

Evidence that methanol inhalation does not induce chromosome damage in mice

Mice were exposed by inhalation to 800 or 4000 ppm methanol for 5 days, and cytogenetic effects were analyzed in blood erythrocytes, lung cells, and testicular germ cells. The results were uniformly negative; no increased frequencies of micronuclei in blood cells, of sister-chromatid exchanges, chromosome aberrations, or micronuclei in lung cells, or of synaptonemal complex damage in spermatocytes were found. From the standpoint of risk assessment, these experimental studies do not reveal any evidence of a cytogenetic hazard associated with inhalation of methanol.

Immunohistologic localization of alpha, mu, and pi class glutathione S-transferases in human tissues

Human alpha, pi, and mu class glutathione S-transferases (GSH S-T) have been localized immunohistologically in a variety of organs. Alpha GSH S-T are found principally in hepatocytes, proximal convoluted tubules of kidney, the deep reticular layer of the adrenal gland, interstitial cells of the testis, and oxyntic cells of the stomach. The pi GSH S-T are present in relative abundance in ductular, as opposed to parenchymal cells in the liver, pancreas, salivary glands, and kidney. The presence of mu GSH S-T in the tissues of certain patients and its absence in the same tissues from other patients has been demonstrated. The pi GSH S-T seems to be most persistently and strongly expressed in tumors but alpha GSH S-T are also found in some neoplasms whereas the mu GSH S-T are occasionally present when the other two transferases are weak or absent.

Sorting minor subpopulations of cells: use of fluorescence as the triggering signal

Flow cytometric cell sorting is commonly used to obtain purified subpopulations of cells for use in in vitro and in vivo assays. This can be time-consuming if the subpopulations of interest represent very low percentages of the cell suspension under study. Often the desired subpopulations are identified by two-color immunofluorescence staining. Generally, cell sorting is performed with a flow cytometer configured to trigger on light scatter signals, then sort windows are set based upon the signals from both fluorescent markers. We demonstrate that triggering the cytometer with the fluorescence signal from antibody staining common to both of the desired subpopulations, then sorting the subpopulations based upon staining of a second marker, substantially increases the speed of cell sorting vis-à-vis traditional methods. This is because undesired events are not analysed, allowing an increase in the throughput rate. While desired subpopulations of cells can be obtained by this method, undesired (i.e., nonstaining) cell "contaminants" increase and may require a second sort. The combined time for the initial enrichment sort and a second sort can be less than sorting once using standard methodology. Alternatively, the degree of contamination may be controlled by adjusting the concentration of the cell suspension and by the sample flow rate.

Genotoxicity of inhibitors of DNA topoisomerases I (camptothecin) and II (m-AMSA) in vivo and in vitro

The present study was designed to determine and compare the clastogenicity of m-AMSA and camptothecin (CAMP) in vivo in mouse bone marrow and peripheral blood lymphocytes (PBLs), and in vitro in mouse lymphoma L5178Y cells. m-AMSA interferes with topoisomerase II to induce double-strand DNA breaks. CAMP interferes with topoisomerase I to induce single-strand DNA breaks. Thus, we expected the two drugs to induce different types of chromosomal aberrations (CAs). However, both drugs produced quantitatively and qualitatively similar numbers and types of aberrations under similar experimental conditions. In mouse bone marrow exposed over and 18-h period, both drugs (3 mg/kg) induced approximately 30 damaged cells, with an average of 0.4 chromatid breaks per cell (in 100 cells analyzed/mouse). In addition, both drugs induced only chromatid-type aberrations in mouse bone marrow in vivo when exposure occurred during G2. Cell cycle specificity was indicated by the absence of CAs when exposure to the drugs occurred in vivo in mouse PBLs during G0. In L5178Y cells, m-AMSA was considerably more potent for the induction of mutations and somewhat more potent for the induction of CAs than CAMP was. In contrast to the in vivo bone marrow results, the drugs induced high levels of both chromatid- and chromosome-type aberrations in vitro. The ultimate types of chromosomal damage induced by m-AMSA and CAMP result from a complex interaction of (i) cell cycle specific variations in topoisomerase enzyme levels, (ii) the abilities of these drugs to interfere with the orderly DNA breakage/reunion associated with topoisomerase activity, and (iii) the processing of the damage resulting from these interactions.

The mass spectra of 4-aminophenanthrene and its trifluoroacetic anhydride and perfluoropropionic anhydride derivatives

Several aminophenanthrenes have been examined with electron impact mass spectrometry. The trifluoroacetic anhydride (TFAA) and perfluoropropionic anhydride (PFPA) derivatives of 4-aminophenanthrene have been studied with electron impact as well as both positive and negative ion chemical ionization mass spectrometry utilizing methane as a reagent gas. The resulting mass spectra indicate a loss of water from the derivatives and a mechanism is proposed to account for this loss. The spectra also indicate unique fragmentation patterns associated with the position of the substituent, particularly the four position which is in the region of the molecule termed the bay region. Another interesting aspect is the spectral differences observed for the TFAA and PFPA derivatives of 4-aminophenanthrene. The positive ion chemical ionization mass spectrum of the TFAA derivative indicates an ion [M + H - H2O]+; however, the mass spectrum of the PFPA derivative of 4-aminophenanthrene indicates no water loss from the [M + H]+ ion. The negative ion chemical ionization mass spectra of the two derivatives are also very different. The mass spectrum of the TFAA derivative shows an [M - 18]- ion and the PFPA derivative shows successive losses of HF with no apparent loss of water.

Identification of organic N-chloramines in vitro in stomach fluid from the rat after chlorination

Amino acids were identified and quantified in the stomach fluid recovered from animals fasted 8, 24, and 48 h. After in vitro chlorination of stomach fluid, three chloramino acids, N-chloroglycine, either N-chloroleucine or N-chloroisoleucine, and N-chlorophenylalanine, were identified by GC/MS analysis of dansylated methyl ester derivatives. Formation of N-chlorovaline and N-chloroserine was suggested by their HPLC retention times, but their identification could not be confirmed by GC/MS data.

Pulmonary blastomycosis: findings on chest radiographs in 63 patients

Posteroanterior and lateral chest radiographs of 63 patients with proved pulmonary blastomycosis were evaluated to determine the most common findings. Included in the analysis were the location of the pulmonary infiltrates, the distribution and parenchymal patterns of disease, and the prevalence of adenopathy, pleural effusions, and/or cavity formation. Blastomycosis pneumonitis involved more than one pulmonary lobe in 21 patients and a single upper lobe in 27 of 63 patients. Forty-eight of the 63 patients had air-space consolidation. In nine of the 63 patients, a pulmonary mass was the major abnormality seen on radiographs. Approximately one fifth of the patients had associated pleural effusions and/or mediastinal or hilar adenopathy. Twenty-three patients (37%) had cavitation within the area of pulmonary consolidation. These findings suggest that blastomycosis should be considered when chest radiographs show air-space infiltrate in the upper lobes or in more than one lobe of the lung, especially when the infiltrate is associated with pleural effusions, cavitation, lymphadenopathy, and/or a paramediastinal mass.

Synthesis and anticonvulsant activity of some new 2-substituted 3-aryl-4(3H)-quinazolinones

A series of 4(3H)-quinazolinones structurally related to 2-methyl-3-o-tolyl-4(3H)-quinazolinone (methaqualone, 3) were synthesized and evaluated for anticonvulsant activity. Preliminary screening of these compounds revealed that 2-[2-oxo-2-(4-pyridyl)ethyl]-3-aryl-4(3H)-quinazolinones 6l and 8i, 8k, and 8p-r having a single ortho substituent on the 3-aryl group had the most promising anticonvulsant activity. Compounds 6l and 8i possessing 3-o-tolyl and 3-o-chlorophenyl groups, respectively, showed good protection against MES- and scMet-induced seizures, combined with relatively low neurotoxicity after intraperitoneal administration in mice. They also exhibited low toxicity in tests for determining the mean hypnotic dose (HD50) and the median lethal dose (LD50). Although these compounds were markedly more potent as anticonvulsants when administered orally in mice and rats, they were also more neurotoxic. This neurotoxicity was particularly acute in oral tests with rats, which resulted in marginal protective indices. In drug differentiation tests, compound 6l was ineffective against seizures induced by bicuculline, picrotoxin, and strychnine, while 8i showed some protection against picrotoxin-induced seizures.

Synthesis and anticonvulsant activity of some new 2-substituted 3-aryl-4(3H)-quinazolinones

A series of 4(3H)-quinazolinones structurally related to 2-methyl-3-o-tolyl-4(3H)-quinazolinone (methaqualone, 3) were synthesized and evaluated for anticonvulsant activity. Preliminary screening of these compounds revealed that 2-[2-oxo-2-(4-pyridyl)ethyl]-3-aryl-4(3H)-quinazolinones 6l and 8i, 8k, and 8p-r having a single ortho substituent on the 3-aryl group had the most promising anticonvulsant activity. Compounds 6l and 8i possessing 3-o-tolyl and 3-o-chlorophenyl groups, respectively, showed good protection against MES- and scMet-induced seizures, combined with relatively low neurotoxicity after intraperitoneal administration in mice. They also exhibited low toxicity in tests for determining the mean hypnotic dose (HD50) and the median lethal dose (LD50). Although these compounds were markedly more potent as anticonvulsants when administered orally in mice and rats, they were also more neurotoxic. This neurotoxicity was particularly acute in oral tests with rats, which resulted in marginal protective indices. In drug differentiation tests, compound 6l was ineffective against seizures induced by bicuculline, picrotoxin, and strychnine, while 8i showed some protection against picrotoxin-induced seizures.

A biomechanical study of suture pullout in linea alba

The relationship of suture bite size, suture diameter, and fascial thickness to strength of wound closure was studied in cadaveric linea alba. All soft tissue was removed from the fascia of 12 abdominal walls that were cut into 346 test sections. A single suture loop was placed in each section, simulating laparotomy closure with interrupted technique. Suture bite size (0.3, 0.6, 0.9, 1.2, 1.5, and 1.8 cm) and gauge (00, 0, 1, and 2) were randomly assigned. The force and energy required to pull out suture loops were measured. Mean linea alba thickness was greater above the linea semicircularis than below (1.19 vs 0.77 mm; p less than 0.001). Similarly, mean pullout force was greater above the linea semicircularis (58.2 vs 31.6 N; p less than 0.001). Regression analysis found that fascial thickness and bite size accounted for 68% of observed variability in pullout force. Suture diameter was unrelated to pullout force. Optimum security was obtained with bites of at least 1.2 to 1.5 cm.

Mechanical prophylaxis of venous thrombosis in patients undergoing craniotomy: a randomized trial

A randomized, prospective clinical trial of 70 patients undergoing craniotomy was performed to compare and evaluate two forms of mechanical prophylaxis of deep vein thrombosis. Thirty-eight patients received antiembolism stockings, whereas 32 patients received external pneumatic compression. Prophylaxis was begun preoperatively and continued intraoperatively and post-operatively until the patients were ambulatory. Impedance plethysmography was used to detect deep vein thrombosis both preoperatively and postoperatively. Two patients, one from each group, developed thromboembolic complications postoperatively. Impedance plethysmography showed false-positive findings in two additional patients. There were no deaths. The data suggest that either form of mechanical prophylaxis is effective against the development of deep vein thrombosis in this high-risk patient population.