Imbrication reconstruction following partial laryngectomy

Experience over a 16-year period with 38 patients who underwent partial laryngectomy with imbrication reconstruction is reviewed. We have found this technique to be an expeditious and highly successful means of eradicating T1 or T2 glottic cancer. The use of the patient's own full-thickness, adjacent normal tissue with imbrication of cartilage produces an adequate airway, an almost normal-appearing larynx, and a remarkable posttreatment voice quality, better results than from most cordectomies or vertical hemilaryngectomies. It is valuable as a salvage procedure after full-course radiation. Imbrication laryngoplasty is an alternative and a preferred modality for treatment of young people with early glottic carcinoma for whom the possible carcinogenic properties of radiation must be considered. The survival results are comparable with the more extensive vertical laryngectomies.

Clonal origins of lymphoproliferative disease induced by Epstein-Barr virus

Analysis of immunoglobulin gene rearrangements in 16 B-cell lineages clonally propagated from two mononucleosis patients supported the notion that mononucleosis is a polyclonal B-lymphoproliferative disorder. Three of seven cell clones from a patient with a fatal B lymphoma revealed the same pattern of immunoglobulin gene rearrangement, indicating that this patient's disease was oligoclonal. The three similar clones were propagated from two sites (blood and spleen), indicating that they represent a metastatic cell lineage which arose during the patient's fatal B lymphoproliferation.

Enteral nutrition in patients receiving mechanical ventilation. Multiple sources of tracheal colonization include the stomach

Nutritional therapy of patients receiving mechanical ventilation includes enteral feeding. To determine the frequency of gastric microbial colonization in patients receiving enteral nutrition, 18 patients with acute respiratory failure receiving ventilation were studied. Multiple sources of tracheal colonization were then evaluated to determine the frequency of tracheal transmission of gastric flora and the relationship of gastric colonization and transmission to nosocomial respiratory infection. The stomach was colonized in every patient who received enteral feeding. Tracheal colonization occurred in 89 percent (16 of 18) of patients. In 12 of these 16 patients, 14 organisms colonized the trachea after transmission from the stomach and/or oropharynx. Thirty-six percent (five of 14) of organisms transmitted to the trachea originated from the stomach, whereas another 36 percent (five of 14) were first recovered from the oropharynx. Four tracheally transmitted organisms were first recovered simultaneously from the stomach and oropharynx. Nosocomial respiratory infection developed in 11 patients (63 percent). Three infections occurred during the six-day study period, one of which was associated with transmission of a gastric organism. Multiple sources of tracheal colonization occur in patients receiving enteral nutrition. The stomach is an important source of tracheal colonization. Enteral nutrition can be associated with gastric flora colonizing the trachea and causing nosocomial respiratory infection.

Prefabricated ossicular homografts in middle ear reconstructions

This paper is a review of 132 cases of ossicular reconstruction utilizing prefabricated homografts by clinical staff members of the UCLA Division of Head and Neck Surgery (specializing in ear surgery) in their private practice over the past decade. Another 20 cases completed over the past 2 1/2 years in the UCLA teaching programme are also reviewed. Although ossicular homografts have been used for some time in middle ear reconstruction, this report presents the innovation of prefabricating homografts into specific shapes that lend themselves appropriately to reconstruction problems. In such an ossicular bank, a variety of different shapes, in a number of sizes, is maintained for quick selection. This greatly decreases operating room time and, in addition, provides an effective method for ossicular reconstruction that has already been applied to a resident training programme. The cases in this review can be divided into 3 basic categories: (1) mastoidectomy ossicular reconstruction; (2) exploratory tympanotomy with reconstruction; (3) stapedectomy. This study indicates that ossicular homografts are very well tolerated in their new transplanted positions. Our very low extrusion rate, extremely rare evidence of absorption, and lack of foreign body reaction to these ossicles coincides with the experience of others. This is an advantage over plastic prostheses. In addition to pre- and postoperative air conduction level data, analysis of changes in bone conduction and speech discrimination scores are also presented to evaluate possible neurosensory damage related to manipulation in placing these ossicles.

Effects of dietary alteration of bicarbonate and magnesium on rat bone

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.

Multicenter study of the clinical efficacy of imipenem/cilastatin for treatment of serious infections

The efficacy and safety of imipenem/cilastatin was evaluated in a multicenter study. For 49 of the 78 patients with 79 infections entered into the study, the clinical and bacteriologic efficacy of therapy could be evaluated. Toxicity data were analyzed for all 79 infections. Overall, 35 of 49 infections were cured or improved: 10 of 11 cases of pneumonia; 8 of 15 cases of pyelonephritis; 4 of 5 cases of osteomyelitis; 3 of 4 intravascular infections; 6 of 9 soft tissue infections; and 4 of 5 miscellaneous infections. There were 13 bacteriologic failures; superinfections with resistant organisms (i.e., Candida albicans, methicillin-resistant Staphylococcus epidermidis, and Pseudomonas maltophilia) occurred in three patients; reinfection with sensitive pathogens complicated one urinary tract infection; relapses developed of five urinary tract infections and of one case of endarteritis; and bacteriologic persistence occurred in three soft tissue infections. Infections with Pseudomonas aeruginosa were the most difficult to treat. In only six of 11 P. aeruginosa infections was both bacteriologic and clinical cure achieved. Adverse effects were minimal; no serious hematologic or hepatic toxicity and no adverse renal effects were noted.

Leishmania infecting man and wild animals in Saudi Arabia. 1. General survey

Using up to 13 enzymes, biochemical characterization of 75 isolates of Leishmania made from man, wild animals and sandflies from a wide variety of localities in the Kingdom of Saudi Arabia has revealed the presence of L. major (two similar zymodemes), L. tropica (two zymodemes) and a parasite of the L. donovani-L. infantum complex. Zymodeme LON-4 of L. major has been found in 52 of 53 isolates so far characterized from man, from one specimen of Phlebotomus papatasi, from 15 Psammomys obesus, from one Meriones libycus and from one dog. One isolate from man has been identified as a new variant of L. major. This variant, zymodeme LON-65, varies from zymodeme LON-4 in a single enzyme. While this is the only example of zymodeme LON-65 identified so far, zymodeme LON-4 has also been obtained from Kuwait and Iraq. These are the first reports of L. major in Meriones libycus from Saudi Arabia and the first proven isolate from the dog in any country. L. tropica was identified from only two foci, whereas L. major appears to be widely distributed in the Kingdom. Two infants with kala-azar were found to be infected with a parasite apparently identical to zymodeme LON-42 of L. donovani (sensu lato) which also occurs in the highlands of Ethiopia.

Infectious mononucleosis: a polyclonal B cell transformation in vivo

We obtained spontaneous formation of Epstein-Barr virus-transformed B lymphocyte colonies from the blood of four patients with mononucleosis with the use of soft-agar medium. The colonies were propagated into separate cell lines and analyzed for their immunoglobulin secretion. Of 52 such lines, 44 produced immunoglobulin composed of a single class of heavy chain and single type of light chain. Among these clonal transformants, 27 (62%) of 44 produced mu-chain, 13 (29%) of 44 produced gamma-chain, and 4 (9%) of 44 produced alpha-chain. Analysis of light-chain secretion revealed that of the 44 cell clones secreting complete, monoclonal immunoglobulin products, 31 produced kappa-chain and 13 produced gamma-chain. One clone secreted mu-heavy chain and no light chain, an observation suggesting the clone is a pre-B cell phenotype. Seven lines derived from clones had aberrant patterns of immunoglobulin secretion that produced either two heavy chains or two light chains. B lymphocytes in different states of immunoglobulin gene expression are, therefore, transformed in vivo by Epstein-Barr virus.

A rapid staining procedure for Anaplasma marginale in bovine erythrocytes

A commercial product that stains cells in less than 1 minute was compared with the Giemsa and the Wright-Giemsa methods for detection of the intraerythrocytic parasite, Anaplasma marginale, in bovine blood smears. The total number of A marginale-infected erythrocytes detected in 5 microscope fields of 18 different samples was determined for each staining procedure. In samples where less than 2% to greater than 25% of the RBC were infected, statistical analysis of the data indicated that the rapid staining method was superior to the Giemsa and Wright-Giemsa methods with regard to determination of the percentage of bovine erythrocytes infected with A marginale.

Effects of ketamine on the adaptive responses of second-order vestibular neurons of the cat

The adaptive characteristics of 80 neurons in the vestibular nuclei of ketamine-anesthetized cats were investigated. All types I and II neurons responded to stimulation of the horizontal semicircular canals by an 8 degree/sec2 stepwise angular acceleration of 40 sec. For the purpose of this study, vestibular adaptation was defined as a decline in response at a rate of greater than -0.01 spikes/sec/sec. According to this criterion, 71 neurons (89 per cent) behaved as adapting neurons, and nine (11 per cent) showed either no adaptation or reverse adaptation. The rate of adaptation varied from neuron to neuron; the average rate was -0.312 spikes/sec/sec. The average resting discharge rate, the maximum response level, and the average adaptation rate were compared with similar neural responses in barbiturate-anesthetized cats. Although the average resting discharge rates of the two groups showed no significant difference, the average adaptation rate and the maximum response level of the ketamine-anesthetized group were significantly higher than those of the barbiturate-anesthetized group. These data suggest that the gain of the second-order neurons is higher and more actively modulated in more alert (ketamine-anesthetized) cats than in barbiturate-anesthetized cats.

Histopathology of neurosensory deafness in sarcoidosis

Sarcoidosis is an idiopathic systemic granulomatous disease which occasionally causes fluctuating auditory and vestibular dysfunction. The temporal bones from a 32-year-old man deaf for 5 years from CNS sarcoidosis were examined histologically and compared with other nervous system tissues. It was found that the acoustic, vestibular, and facial nerves were involved in a striking perivascular lymphocytic infiltration resulting in myelin and axonal degeneration. The cochlear and labyrinthine neuroepithelium and stria vascularis had degenerated. It is hypothesized that neurosensory deafness and vestibular dysfunction in sarcoidosis starts as a reversible neuropathy. In some patients, an ischemia secondary to the vasculitis results in irreversible damage to the inner ear neuroepithelium.

Prospective randomized reappraisal of 5-fluorouracil in metastatic colorectal carcinoma. A comparative trial with 6-thioguanine

In order to redefine the effectiveness of 5-fluorouracil (5-FU) as palliative therapy in patients with metastatic colorectal carcinoma, and to compare the effectiveness of 6-thioguanine (6-TG) with that of 5-FU, we studied 176 patients with metastatic colorectal carcinoma in a randomized prospective trial (SEG 79G1268 ). The pretreatment performance status of all patients was greater than 50% (ambulatory), and there was an equal distribution of patients with favorable pretreatment characteristics into each of the treatment regimens. Complete responses were only seen to 5-FU, but were obtained in only 3% of instances. The overall complete plus partial response rates were not different for 5-FU (8%) versus 6-TG (3%), or for patients who had shown prior progression on chemotherapy and who then received 6-TG in a nonrandomized fashion (7%). The time to tumor progression on each of the treatment programs was similar, 1.0 months. Survival was also similar in each regimen in the randomized study (6.3 months for 5-FU versus 7.9 months for 6-TG). However, survival was only 4.8 months for patients with previously drug-resistant tumors treated with 6-TG in the nonrandomized arm. In 16 patients failing 6-TG who then received 5-FU, there were no objective responses. Similarly, in patients failing 5-FU on this study who then received 6-TG, there were no responses in nine patients. Dose-limiting toxicity was observed in 40% to 51% of patients, and consisted of myelosuppression, vomiting, or diarrhea. It is concluded that 5-FU is a minimally effective agent in a very small number of patients with metastatic colorectal carcinoma. The drug 6-TG is equally ineffective in this setting. Alternative treatment programs to the systemic use of 5-FU should be considered in patients requiring palliative chemotherapy.

A histological comparison of the temporal bone in strangulation and drowning

The temporal bones from a two year old drowning victim are compared with those of a 13 month old strangulation victim. Tympanomastoid hemorrhage and submucosal edema and petechiae with moderate vascular congestion were characteristic in drowning. Marked congestion with edema but no sign of hemorrhage was found in strangulation. It is concluded that respiratory effort against a closed glottis is not solely responsible for the tympanomastoid hemorrhage known to occur frequently as a result of drowning.

Acute myelogenous leukemia as a second malignant neoplasm following the successful treatment of advanced Hodgkin's disease

Of 209 Hodgkin's disease patients treated at least 6 months with a five-drug combination of induction chemotherapy and having a complete remission, four patients developed acute myelogenous leukemia (AML) as a second malignant neoplasm. The overall relative risk for development of AML is 185.0 (P less than 0.05) and the mean time to occurrence of AML is 5.3 years (median, 5.25 years). When examining patient subgroups, the highest relative risk noted was 338.5 (P less than 0.05) for that group of patients receiving an additional 6 months of postinduction MOPP (nitrogen mustard, vincristine, procarbazine, and prednisone). Patients receiving only 6 months of induction BVCPP (BCNU, vinblastine, cyclophosphamide, procarbazine, and prednisone) had a relative risk of 166.2 (P less than 0.05). These data results are consistent with previous reports that patients treated for Hodgkin's disease are at high risk for development of AML. However, to date, no patients in this series have developed second malignancies other than AML.

Bacteriological study in chronic maxillary sinusitis

The bacterial findings of 73 maxillary sinuses in 48 patients with chronic maxillary sinusitis, together with 7 non-inflamed sinuses, are reported. Employing an intraoperative technique and simultaneous collection of 3 different types of specimens in the present investigation made possible comparison of their bacterial characteristics. The results indicated that intraoperative culture of antral mucosa seems to provide the most reliable finding of bacterial flora in chronic maxillary sinusitis. The anaerobic bacteria were never found in the mucosal culture of non-inflamed sinus. The anaerobes appeared to invade the sinus cavity following the sealing of the ostium through the lymphatic or venous system and maintain the inflammatory process. Microbiological analysis of the results between the infected and non-inflamed sinuses established anaerobic bacteria as the most important pathogen in chronic maxillary sinusitis. The predominant anaerobes recovered in descending order of frequency were Veillonella sp., Peptococcus sp., Propionibacterium acne and anaerobic nonspore-forming GPB. Statistical analysis of the results of mucosal culture of inflamed and control materials demonstrated that those aerobic and faculatative bacteria recovered in the inflamed sinus appeared to be the normal inhabitants of non-inflamed sinus mucosa. The presence of normal flora in the normal healthy sinus mucosa may explain the chain of events that follows the occlusion of the ostium. These aerobic bacteria may become pathogenic and play a role in the pathogenesis of sinusitis.

Effects of age on responses to treatment and survival of patients with multiple myeloma

The elderly patient with malignancy is often considered a poor risk for treatment. To assess the effect of age on the treatment of one such disease, multiple myeloma (a disease with increased incidence in the elderly), a study was made of 280 patients treated with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), cyclophosphamide and prednisone on a Southeastern Cancer Study Group protocol. Initial response rates after six months of treatment were equivalent for the older compared with the younger age groups, with a slightly longer remission duration for those over 70. Likewise, survival was equivalent for the older patients. This was not the result of selection of older patients with less advanced disease, since the proportion with both good and poor risk factors are not significantly different in the various age groups. Moreover, for patients with each of the prognostic factors, older patients responded at least as well as younger patients. There were no significant differences among the age groups in gastrointestinal, skin, hair, or hematologic toxicity, although there was a slightly higher incidence of mild granulocyte and platelet toxicity in patients over 60. These findings are in contrast to the widely held belief that older patients cannot tolerate chemotherapy. On the contrary, they suggest that the elderly patient with myeloma may be expected to respond and survive, without excessive toxicity, at least as well as a younger counterpart with similar prognostic factors.

Postmastectomy adjuvant chemotherapy with or without radiation therapy in women with operable breast cancer and positive axillary lymph nodes: the Southeastern Cancer Study Group experience

Between September 1976 and June 1982, 308 patients with operable breast cancer with 1-3 involved axillary nodes were stratified according to institution, type of mastectomy, and time from surgery to protocol entry, and then randomized to receive either six or 12 months of adjuvant chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). With a median time of follow-up of 33 months, relapse rates among 181 reviewed and evaluable patients are 20/85 (23.5%) for pre- and 23/96 (24%) for postmenopausal patients. Results for premenopausal women, while better than historical controls at a similar time interval, appear inferior to other published adjuvant studies (e.g., NSABP and Milan). Although total relapse rates were 23/100 (23%) for six months and 20/81 (25%) for 12 months of therapy, suggestive differences were encountered by menopausal status with early trends favoring 12 months of treatment for premenopausal patients and six months of treatment for postmenopausal patients. During this same period, 283 patients with four or more involved axillary nodes were randomized to 1-3 treatment arms: six months of CMF, six months of CMF preceded by local-regional x-ray therapy (XRT), or 12 months of CMF. The latter arm was closed in February 1980 while the two six-month chemotherapy arms remain open as of January 1983. Relapse rates for 174 reviewed and evaluable patients on the three arms include: 27/76 (36%) for six months CMF, 15/54 (28%) for XRT and CMF, and 24/44 (45%) for 12 months CMF. Local-regional relapse rates were 12/120 (10%) for the combined two non-XRT arms and 3/54 (6%) for the XRT treatment arm (p = 0.34). Thus, at this early stage of follow-up there are still no statistically significant differences between six or 12 months of adjuvant CMF therapy and neither definite beneficial nor detrimental effects of prechemotherapy adjuvant radiation therapy. Longer follow-up will be needed to provide definitive conclusions.

Hidradenitis suppurativa: evidence for a bactericidal defect correctable by cholinergic agonist in vitro and in vivo

Hidradenitis suppurativa (HS) affects the apocrine sweat glands, giving chronic recurrent abscesses of axillary and perineal areas. We report a patient who had a defect in polymorphonuclear leukocyte killing of bacteria associated with low levels of intracellular cyclic GMP. This defect was corrected with a cholinergic agonist in vitro. Treatment of the patient with a cholinergic agonist, bethanechol chloride, resulted in prolonged clinical improvement, normal bactericidal function, and normal levels of intracellular cyclic GMP. The possible mechanisms responsible for the bactericidal defect and for the patient's improvement are discussed.

Trimethoprim-sulfamethoxazole and trimethoprim alone for prophylaxis of infection in granulocytopenic patients

Prophylactic trimethoprim-sulfamethoxazole (TMP-SMZ) has been shown to reduce the incidence of fever, parenteral antibiotic usage, and infections with gram-negative bacteria in hospitalized patients with neutropenia. Furthermore, TMP-SMZ was found to be equivalent to or better than oral, nonabsorbable antibiotics in direct comparisons and to have an additive effect when given together with other oral, nonabsorbable antibiotics. Adults given TMP-SMZ continuously had fewer readmissions for infection than did controls given TMP-SMZ only while hospitalized. TMP-SMZ used continuously in children with acute leukemia was effective in preventing bacterial and Pneumocystis carinii infections. For prophylaxis in granulocytopenic patients, TMP appeared equivalent to TMP-SMZ both in efficacy and incidence of side effects. However, TMP was less effective in suppressing gastrointestinal flora, including TMP-resistant gram-negative rods. Thus, TMP-SMZ has some role in preventing infections in high-risk patients, but further studies, especially comparisons with untreated patients may still be required. TMP used alone offers little advantage and has the theoretical disadvantage of not preventing infections caused by P. carinii or TMP-resistant gram-negative bacteria.

Herpes simplex encephalitis. Clinical Assessment

Continuing evaluations of antiviral agents for treatment of herpes simplex encephalitis (HSE) provided an opportunity to collect clinical data from 113 patients in whom the diagnosis was proved by viral isolation. Occurrence of HSE was in all ages and in both sexes and was nonseasonal. Characteristically, patients had behavioral changes, fever, confusion, speech disturbances, and, less frequently, seizures. The EEG was the most useful neurodiagnostic aid followed by technetium and computed axial tomographic scans. Employing a logistic regression model for variable selection, the diagnosis could be predicted by clinical findings and neurodiagnostic tests in 83% of the proved cases, but the evidence in 25% was falsely positive. There was evidence of localization by either clinical or neurodiagnostic assessment in all patients with proved disease. Among patients wtih negative findings for HSE, similar focal findings predominated in all but a few. The CSF and brain scans were normal in many patients with proved HSE. This extensive clinical experience in patients wtih diagnosis proved by viral isolation shows that diagnosis cna be confirmed only by brain biopsy.

Isolation of novel antibiotics X-14667A and X-14667B from Streptomyces cinnamonensis subsp. urethanofaciens and their characterization as 2-phenethylurethanes of monensins B and A

Antibiotics X-14667A (1) and X-14667B (2) are novel monovalent polyether antibiotics of the spiroketal type isolated from fermented cultures of Streptomyces cinnamonensis subsp. urethanofaciens together with monensin (3), its lower homolog, factor B (4) and 1,3-diphenethylurea (6). By a combination of microanalysis, mass spectrometry and 13C nmr, antibiotics X-14667A and B have been shown to be natural 2-phenethylurethanes of monensin B and A respectively. Both structures have been confirmed by reacting the appropriate monensin with 2-phenethylisocyanate to yield semi-synthetic compounds that are identical to the natural products.

Comparative activities of moxalactam (LY 127935) a new semisynthetic 1-oxa-beta lactam antibiotic with 7 other antibiotics against type b Haemophilus influenzae

A total of 59 clinical isolated strains of Haemophilus influenzae type b, including 22 beta-lactamase-positive strains, were tested against moxalactam (LY 127935), a new 1-oxa-beta-lactam antibiotic and compared with other antibiotics: cefamandole, cefoxitin, ceforanide, ampicillin, ticarcillin, chloramphenical and trimethoprim/sulfamethoxazole (TMP/SMZ) by using an agar dilution susceptibility test and bacterial killing rate study. With beta-lactamase negative H. influenzae all 37 strains were inhibited by ampicillin at concentration less than or equal to 0.2 microgram/ml, in contrast all beta-lactamase positive strains were exhibited by a range from 3.2 micrograms/ml to 25 micrograms/ml. Ticarcillin inhibited 100% of non-beta lactamase strains at 0.4 micrograms/ml in contrast to those beta-lactamase producing strains the range was from 0.8 microgram/ml to 12.5 micrograms/ml. All strains were inhibited by 0.8 microgram/ml of chloramphenicol and by 0.078/1.56 microgram of TMP/SMZ per ml. Among the beta-lactam antibiotics, moxalactam (LY 127935) show 100% inhibited all strains by 0.1 microgram/ml in comparison with cefamandole, cefoxitin and ceforanide most strains inhibited by 0.4 microgram/ml, 2 micrograms/ml and 4 micrograms/ml, respectively. From the killing curve study, during the first 6 hours, each antibiotic had the effect of inhibition growing of both strains of H. influenzae. But after 24 hours incubation, only moxalactam (LY 127935) showed bactericidal effect. These data indicate that moxaladam, a new 1-oxa-beta-lactam antibiotic, had superior inhibitory activity and killing effect against both beta-lactamase producing and non-beta-lactamase producing strains of H. influenzae type b.

Simultaneous Streptococcus and picornavirus infection. Muscle involvement in acute rhabdomyolysis

Streptococci seldom invade muscle in healthy people with intact integument. However, infection with another agent simultaneously may change this general observation. In a two-week period we encountered dual infections with group A, beta-hemolytic streptococci and a picornavirus in each of two hospitalized patients. Both were acutely ill; one died. Renal failure developed in the patient who survived and rhabdomyolysis was demonstrated in the patient who died. Picornavirus titer increases were demonstrated in the patient who survived, and viral inclusions in muscle cells were demonstrated by light microscopy in necropsy specimens and confirmed by electron microscopy in the second patient. We believe that streptococcal invasion of muscle may be facilitated during an outbreak of certain picornavirus infections.

Mutagenicity of nitrosated cimetidines

Dinitrosocimetidine and mononitrosocimetidine were tested in a series of short term assay systems. Both compounds were mutagenic in the absence of rat liver microsomes. The dinitrosocimetidine produced higher mutagenic or clastogenic effects at concentrations that were 50 to 500 times lower than the concentrations at which the mononitrosocimetidine produces its maximum effects. The most sensitive short term assay system was the Chinese hamster ovary cell culture system. Dinitrosocimetidine caused sister chromatid exchanges at a concentration of 10(-8) M and chromosome aberrations at 10(-7) M in this system. Dinitrosocimetidine had moderate activity in the bacterial short term assay systems. In the Ames test, strain TA 100 was the most sensitive. The compound was of lower activity in the E. coli WP-2 and the E. coli rec- systems.

Penetration of cefoxitin into human cerebrospinal fluid: comparison with cefamandole, ampicillin, and penicillin

Single, intravenously administered doses of cefoxitin and cefamandole did not penetrate into cerebrospinal fluid of normal humans. Multiple-dose administration with or without probenecid facilitated penetration of both antibiotics into the cerebrospinal fluid. Preliminary data showed that cefoxitin penetrated into cerebrospinal fluid of patients with inflamed meninges even when administered in a single dose without probenecid. However, the concentrations of cefoxitin in the cerebrospinal fluid of the individuals studied were not within the therapeutic range.

Nafcillin-associated granulocytopenia

Three patients treated with nafcillin developed granulocytopenia. Only three other such cases have been reported. This complication is most likely due to a direct toxic effect on the bone marrow; markers for an immunologically mediated mechanism have not been found. Nafcillin-associated granulocytopenia usually occurs during the third week of therapy and remits spontaneously with prompt cessation of nafcillin administration.