Overwhelming postsplenectomy infection in a patient with penicillin-resistant Streptococcus pneumoniae.

Overwhelming postsplenectomy infection is a fulminant process that carries a poor prognosis. Streptococcus pneumoniae is the most likely organism to cause disease. Infection with penicillin-resistant S pneumoniae is increasing; its prevalence ranges from 6.6% to 50% in the United States. If meningeal involvement with resistant pneumococcus is suspected, it should be treated with a third-generation cephalosporin and vancomycin hydrochloride. The long-term management of asplenic patients should focus on preventing infection. The current guidelines and recommendations for vaccination are reviewed. Educating these patients to contact their physician at the first sign of minor illness is also beneficial. The use of antibiotic prophylaxis remains a controversy and is best left to the discretion of the physician.

Cerebellar disorganization characteristic of reeler in scrambler mutant mice despite presence of reelin.

Analysis of the molecular basis of neuronal migration in the mammalian CNS relies critically on the discovery and identification of genetic mutations that affect this process. Here, we report the detailed cerebellar phenotype caused by a new autosomal recessive neurological mouse mutation, scrambler (gene symbol scm). The scrambler mutation results in ataxic mice that exhibit several neuroanatomic defects reminiscent of reeler. The most obvious of these lies in the cerebellum, which is small and lacks foliation. Granule cells, although normally placed in an internal granule cell layer, are greatly reduced in number ( approximately 20% of normal). Purkinje cells are also reduced in number, and the majority are located ectopically in deep cerebellar masses. There is a small population of Purkinje cells ( approximately 5% of the total) that occupy a Purkinje cell layer between the molecular and granule cell layers. Despite this apparent disorganization of Purkinje cells, zebrin-positive and zebrin-negative parasagittal zones can be delineated. The ectopic masses of Purkinje cells are bordered by the extracellular matrix protein tenascin and by processes containing glial fibrillary acidic protein. Antibodies specific for these proteins also identify a novel midline raphe structure in both scrambler and reeler cerebellum that is not present in wild-type mice. Thus, in many respects, the scrambler cerebellum is identical to that of reeler. However, the scrambler locus has been mapped to a site distinct from that of reelin (Reln), the gene responsible for the reeler defect. Here we find that there are normal levels of Reln mRNA in scrambler brain and that reelin protein is secreted normally by scrambler cerebellar cells. These findings imply that the scrambler gene product may function in a molecular pathway critical for neuronal migration that is tightly linked to, but downstream of, reelin.

Synovial fluid levels of fluconazole in a patient with Candida parapsilosis prosthetic joint infection who had an excellent clinical response.

A 73-year-old woman presenting with persistent swelling of the right knee 30 months after total joint arthroplasty was found to have a Candida parapsilosis infection. Treatment with fluconazole resulted in full recovery.

Assessment of antimicrobial penetrance into the pancreatic juice in humans.

The penetrance of mezlocillin, metronidazole and trimethoprim-sulfamethoxazole into the pancreatic juice of humans was measured in ten patients convalescing from acute pancreatitis at the time of endoscopic retrograde cholangiopancreatography. Therapeutic levels were obtained in the serum for all three antimicrobial agents; simultaneously aspirated nonbile stained pancreatic juice contained therapeutic levels of metronidazole and trimethoprim-sulfamethoxazole. Mezlocillin was not present in a therapeutic level in any patient with nonbile stained pancreatic fluid.

Assessment of pancreatic ductal penetration of antibiotics.

Pancreatic ductal penetration of antibiotics is not uniform. Antibiotic therapy for pancreatic and pancreatic related infections, theoretically, is enhanced by drugs that reach the ductal system. The pancreatic ductal penetrance of Cefamandol (1 gm), Amikacin (7.5 mg/kg), and Chloramphenicol (1 gm) given as a single intravenous dose prior to endoscopic retrograde cholangiopancreatography was studied in ten patients. Serum and pancreatic juice were collected simultaneously, frozen, and later assayed for antibiotic concentration. Each antibiotic achieved its expected therapeutic serum level. In contrast, pancreatic ductal levels of Cefamandol and Amikacin were subtherapeutic, whereas Chloramphenicol levels were therapeutic. Further studies are needed to identify other antibiotics with good pancreatic ductal penetrance.

Vidarabine encephalopathy.

Vidarabine (adenine arabinoside, ara-a) has been found to be useful in the treatment of various viral infections. Its adverse neurological effects include tremor and encephalopathy. Two cases of vidarabine encephalopathy are reported and the five other cases in the literature are reviewed. The clinical features of the tremor and encephalopathy are discussed.

Possible pseudoresistance of Streptococcus pneumoniae to penicillin G in a patient with a mixed pneumococcus-Staphylococcus aureus pneumonia.

We report the case of a 53-year-old woman with a mixed pneumococcus-staphylococcus pneumonia, in which both organisms were recovered from both sputum and blood. Streptococcus pneumoniae persisted in sputum 48 hours after initiation of high-dose intravenous penicillin G. When nafcillin was substituted for penicillin G, both pneumococci and staphylococci were eradicated from blood and sputum. This strain of Streptococcus pneumoniae was highly susceptible to penicillin G, but the associated strain of Staphylococcus aureus was not. The staphylococcus produced large amounts of a penicillin -degrading betalactamase . We reviewed the records of ten cases of pneumococcus pneumonia from the Wayne State University-Detroit Medical Center admitted from March 1978 to April 1981, in which sputum cultures were repeated within one to ten days after penicillin G had been initiated. At second cultures of sputum, Streptococcus pneumoniae was recovered in none of these latter cases. We further showed that on a blood agar culture plate in the presence of penicillin G, a beta-lactamase positive strain of Staphylococcus aureus allowed growth of Streptococcus pneumoniae. Therefore, despite penicillin therapy, Staphylococcus aureus in sputum may facilitate the persistence of Streptococcus pneumoniae.

The value of prophylactic antibiotic therapy during endoscopic retrograde cholangiopancreatography.

Prophylactic antibiotics have been recommended during endoscopic retrograde cholangiopancreatography in the hope of preventing septic complications. However, their effectiveness has not been proved clinically. In this study, the ability of the pancreas to secrete ampicillin, gentamicin and clindamycin after a single intravenous dosage, given prior to endoscopic retrograde cholangiopancreatography in 12 patients, was examined. Simultaneously obtained serum antibiotic levels were within the expected therapeutic range. In contrast, pancreatic ductal levels of ampicillin and gentamicin were too low to be measured in most patients. Most patients had measurable clindamycin levels which ranged from 12.0 to 3.1 micrograms per milliliter in seven patients and was 8.0 micrograms per milliliter in one patient. Parenteral prophylactic antibiotic coverage for endoscopic retrograde cholangiopancreatography is ineffective with gentamicin or ampicillin. Clindamycin may be of value, but it needs further study at higher dosages.

Community-acquired methicillin-resistant Staphylococcus aureus endocarditis in the Detroit Medical Center.

Between June 1980 and September 1981 we evaluated 24 cases of endocarditis from methicillin-resistant Staphylococcus aureus. All of the cases occurred in drug addicts and all were community-acquired. The patients ranged in age from 21 to 59 years and represented an older population than that generally reported for bacterial endocarditis in addicts. Men and women were equally represented (one man presented twice). This unusually high proportion of women may reflect a difference in the rate and location of carriage of methicillin-resistant S. aureus compared with that of methicillin-sensitive staphylococci. Three patients died, one of whom had signed out of the hospital on the 14th day and returned moribund 27 days later. Vancomycin treatment for 28 days was adequate therapy for most patients.

Phosphorus and divalent cations in dog, rabbit, and human platelet dense bodies as deduced from electron microprobe studies of air-dried whole mounts.

Dense bodies have been examined by electron microprobe techniques in air-dried whole mounts of dog, rabbit, and human platelets. On the basis of measurement of the intensities of the X-rays produced when dense bodies are probed for 100 seconds, dog and rabbit platelet dense bodies contain on the average less phosphorus and calcium, but more magnesium, than do human platelet dense bodies. Dense bodies of dog and rabbit platelets thus appear to resemble more closely those of pig platelets than those of human platelets.

Evaluation of the utility of air-dried whole mounts for quantitative electron microprobe studies of platelet dense bodies.

A variety of electronmicroscope techniques have been used to examine how the air-drying process may affect the dense bodies in whole mounts of platelets. (a) Selected-area-diffraction and electron microprobe studies suggest that the air-drying process can result in the formation of crystalline precipitates of sodium chloride on grid films and platelets. However, no crystals were detected in the calcium-and-phosphorus-containing matrix of dense bodies. (b) Tilting studies show that dense bodies in human platelets are spherical or ellipsoidal in shape. Dense bodies in rabbit platelets, in contrast, appear flattened in a horizontal plane. (c) Human-platelet dense bodies probed with a small (20 nm diameter) spot vary widely in their peak/background ratios for calcium and phosphorus-a finding that suggests that the two elements may not be evenly distributed throughout the dense-body matrix. Nevertheless, when dense bodies are probed with a larger (200 nm diameter) spot, they do not appear to differ appreciably among themselves in their calcium or phosphorus content. The data suggest that with human platelets, air drying may be a preparative procedure which permits comparison by microprobe techniques of dense-body matrix content in platelet populations.

Antibiotics in trauma.

The injured patient frequently develops serious infection. Prophylactic antibiotics can decrease the rate of acquisition of certain infections in the trauma patient. Hospital-acquired infection with resistant microorganisms is an increasing problem. Antibiotics may predispose the patient to certain serious infections. An understanding of the biology of infectious diseases and the clinical pharmacology of antibiotics helps the surgeon treat infection correctly.

Pulmonary infections.

It is likely that nosocomial pneumonias will continue to be a problem in critical-care areas. If there are to be breakthroughs, they will probably come in the area of prevention, not treatment. Scrupulously sterile techniques when using inhalation therapy equipment, suctioning patients, and changing tracheal tubes remains the mainstay of prevention. Early recognition and aggressive therapy of nosocomial pneumonias have had limited success in decreasing morbidity and mortality rates.

An estimate of the course of herpes simplex virus encephalitis.

Serologic responses, physical findings, and survival were studied in 51 cases of proved (14 patients) or presumptive (37 patients) herpes simplex encephalitis occurring in North America between 1965 and 1972. On the basis of a statistical analysis of 16 serological parameters tested in both groups, presumptive cases are likely similar to definitive cases. Using this assumption, the following tentatives conclusions are possible. Complement-fixing antibodies may be more sensitive measures of rises in anti-herpes simplex virus antibodies than are conventional or complement-requiring neutralizing or passive hemagglutinating antibodies. Mortality in herpes simplex virus encephalitis may vary from 0 to 80% and may be predictable depending upon the occurrence of seizures, paralysis and coma. Coma seems to dictate the dour prognosis. When 51 cases of herpes simplex virus encephalitis reported in the literature by others between 1944 and 1972 were analyzed by this method, a comparably varied mortality was obtained. It did not appear that treatment with idoxuridine increased the likelihood of survival.