First transmission electron micrograph of continuous mitotic spindle fibers between polar area and chromosome ends

Congenital and/or nevoid skin disorders following the lines of Blaschko may have a delayed onset after birth. They have to be differentiated from acquired dermatoses exhibiting the same linear pattern. In common dermatoses, such as psoriasis or lichen planus, lesions in a blaschkolinear distribution most often occur together with scattered lesions, but occasionally they may be isolated. Less common self-limited dermatoses such as lichen striatus and adult blaschkitis always present in a blaschkolinear fashion. In these diseases, or some other conditions occasionally distributed along these lines (chronic graft versus host reaction, fixed drug eruption, lupus erythematosus, atopic dermatitis, etc.), the cause of the disease may lead to the unmasking of tolerance to an abnormal keratinocyte clone that remained hidden in these lines. In addition to epithelial cells, other cells may be involved in the occurrence of acquired blaschkolinear dermatoses. In linear atrophoderma and linear fibromatosis, the histogenesis seems to involve hypothetic dermal clones. The extension of an acquired dermatosis on a preexisting linear nevoid disorder is an argument in favor of an early embryonic somatic mutation of a skin cell line.     

Magnetic resonance spectroscopy in toxic encephalopathy and neurodegeneration

Magnetic resonance spectroscopy allows neurochemistry to be probed noninvasively in vivo. Recent advances in our understanding of the biochemical significance of the various neurochemicals that are observable allow a variety of pathologic states of relevance to encephalopathies and neurodegenerative disorders to be observed. Measurements of brain glutamate and glutamine allow observation of neuronal/glial substrate cycling and ammonia detoxification. Myo-inositol allows changes in cerebral osmolarity and gliosis to be observed. N-acetylaspartate is a marker of neuronal health and number. Lactate allows nonoxidative glycolysis to be observed. These molecules are now being used to ask etiologic questions that are of relevance to encephalopathies and neurodegeneration, as well to probe longitudinally both natural history and therapeutic interventions in these conditions. Combined with recent advances in anatomic magnetic resonance imaging as well as perfusion magnetic resonance imaging, magnetic resonance spectroscopy has the potential to aid greatly in our understanding of neuronal dysfunction in a wide variety of neurologic pathologies, even in single patients.     

Distal splenorenal shunt: role, indications, and utility in the era of liver transplantation

HYPOTHESIS: The distal splenorenal shunt (DSRS) continues to play an important role in the management of recurrent variceal bleeding with minimal negative impact on subsequent orthotopic liver transplantation (OLT). DESIGN: Case-control study. SETTING: Hepatobiliary surgery and liver transplantation unit in a tertiary referral medical center. PATIENTS: From August 1, 1985, through October 31, 1997, a single team of surgeons performed 81 DSRS procedures for recurrent variceal hemorrhage. Eleven patients undergoing OLT subsequent to DSRS were compared with a group of 274 patients undergoing OLT without any previous shunt during the same period. MAIN OUTCOME MEASURES: Operative time, use of blood products, length of hospital stay, perioperative complications, and survival rates. RESULTS: Operative (30-day) mortality for DSRS was 6% (n = 5). From follow-up information available for 74 patients, the 1- and 5-year survival rates were 86.4% (n = 64) and 74.3% (n = 55), respectively. Recurrent variceal bleeding and hepatic encephalopathy occurred in 5 (6.8%) and 11 patients (14.9%), respectively, after DSRS. In 9 patients, DSRS was used as salvage for failed transjugular intrahepatic portosystemic shunt. CONCLUSIONS: Distal splenorenal shunt is a safe, durable, and effective treatment for controlling recurrent variceal hemorrhage in patients with acceptable operative risk and good liver function. It does not compromise future liver transplantation and can considerably delay the time until transplantation is required. Given the early occlusion rate and need for constant surveillance, transjugular intrahepatic portosystemic shunting should be reserved for patients with Child C classification cirrhosis with chronic hemorrhage or intractable ascites or as an emergency procedure for patients with uncontrollable bleeding using endoscopic therapy.     

No fathers' names: a risk factor for infant mortality in the State of Georgia, USA

Many studies have explored maternal and infant factors as risks for infant mortality, but little attention is given to paternal factors. In Georgia, listing a father's name on the birth certificate is optional for married couples and possible after paternal acknowledgment for unmarried couples. The authors evaluated father's name reporting as a paternity measure and risk for infant mortality. Using the linked 1989-1990 birth and death certificates of singleton Georgia infants to calculate relative risks (RRs), infant mortality rates for 38,943 infants with no father's names listed were compared to rates for 178,100 with father's names listed. Compared with the rate for married women listing names, the death rates were higher for unmarried mothers not listing fathers (relative risk, RR = 2.5; 95% CI 2.3-2.7), unmarried mothers listing fathers (RR = 1.4; 95% CI 1.3-1.6), and married women not listing fathers (RR = 2.3; 95% CI 1.6-3.1). Increased risks remained after stratifying by maternal race, age, adequacy of prenatal care and medical risks; and congenital malformations, birthweight, gestational age, and small-for-gestational age. Using logistic regression to examine for effect modification and to adjust for these factors together, the adjusted relative risks for death varied across different groups without fathers' names, regardless of marital status. For example, it remained statistically higher for infants with no father listed and without effect-modifying conditions such as low birthweight (estimated RR = 2.0; 95% CI 1.6-2.4). Although these findings suggest paternal involvement, as measured by listing fathers' names, is protective against low birthweight and infant mortality, further evaluation is needed.     

Effect of A-ring modifications on the DNA-binding behavior and cytotoxicity of pyrrolo[2,1-c][1,4]benzodiazepines.

Several A-ring-modified analogues of the DNA-binding antitumor agent DC-81 (5) have been synthesized in order to study structure-reactivity/cytotoxicity relationships. For two molecules (23 and 30) the modifications required the addition of a fourth ring to give the novel dioxolo[4,5-h]- and dioxano[5,6-h]pyrrolo[2,1-c][1, 4]benzodiazepin-11-one (PBD) ring systems, respectively. Another three analogues (34, 38, and 48) have the native benzenoid A-ring replaced with pyridine, diazine, or pyrimidine rings to give the novel pyrrolo[2,1-c][1,4]pyridodiazepine, pyrrolo[2,1-c][1, 4]diazinodiazepine, and pyrrolo[2,1-c][1,4]pyrimidinodiazepine systems, respectively. The other new analogues (16a,b) have extended chains at the C8-position of the DC-81 structure. During the synthesis of these compounds, a novel tin-mediated regiospecific cleavage reaction of the dioxole intermediate 18 was discovered, leading to the previously unknown iso-DC-81 (20). In addition, an unusual simultaneous nitration-oxidation reaction of 4-(3-hydroxypropoxy)-3-methoxybenzoic acid (8) was found to produce 3-(4-carboxy-2-methoxy-5-nitrophenoxy)propanoic acid (9), a key intermediate, in high yield. In general, the results of cytotoxicity and DNA-binding studies indicated that none of the changes made to the A-ring of the PBD system significantly improved either binding affinity or cytotoxicity in comparison to DC-81. This result suggests that the superior potency of natural products such as anthramycin (1), tomaymycin (2), and sibiromycin (3) is due entirely to differences in C-ring structure, and in particular exo or endo unsaturation at the C2-position and C2-substituents containing unsaturation. This study also provided information regarding the influence of A-ring substitution pattern on the relative stability of the interconvertible N10-C11 carbinolamine, carbinolamine methyl ether, and imine forms of PBDs.     

Methods of measuring susceptibility of anaerobic bacteria to trovafloxacin,including quality control parameters

Three methods approved by the National Committee for Clinical Laboratory Standards for testing the susceptibility of anaerobic bacteria were used to evaluate the fluoroquinolone, trovafloxacin. The methods gave essentially comparable results with 126 anaerobes and with three quality control strains. A collaborative study defined the quality control range for trovafloxacin MICs. Trovafloxacin had good in vitro activity against the more common anaerobes (MIC 90 <- 2.0 (g/ml).Trovafloxacin (CP-99,219) is a fluoroquinolone with a broad spectrum of antibacterial activity (1–3). Its in vitro spectrum includes many anaerobic bacteria (4).The National Committee for Clinical Laboratory Standards (NCCLS) currently recommends three different methods for testing the susceptibility of anaerobic bacteria (5). The standard reference method is an agar dilution procedure using Wilkins-Chalgren agar. Two alternative methods are an agar dilution technique using Brucella blood agar and a microdilution procedure using a broth version of Wilkins-Chalgren medium. It is important to determine whether these three procedures actually produce identical test results with each antimicrobial agent likely to be tested against anaerobes.     

A cold chain friendly to people ... and the environment

The vaccination cold chain makes vaccination possible even in the most remote areas of the tropics. Efforts to achieve the World Health Organization's goal of 90% full vaccination of the world's children by the year 2000 have led to the provision of more than 2000 vaccine refrigerators in formerly war-torn Ethiopia (which has achieved 65% coverage) and 124 solar medical refrigerators in Eritrea (which has 44% coverage). Many more medical refrigerators will be necessary to extend the cold chain to those who need it most, and the cold chain requires trained workers to transport the refrigerated vaccines in ice packs kept at the correct temperature. Each ice pack should have a cold chain monitor card that changes color to indicate temperature variations and an attached vial that shatters if it becomes overfrozen. Solar-powered medical refrigerators are reliable and cost effective, but their production has slowed because of pressure to make them free of CFCs. Very few solar models have been approved and tested by the World Health Organization; one is the DULAS VC150F, which was developed over 10 years ago. In order to generate support for solar medical installations, DULAS also offers the training integral to maintenance of a cold chain.