The C-terminal domains of gammaS-crystallin pair about a distorted twofold axis

The 2-domain gammaS-crystallin, a highly conserved early evolutionaryoff-shoot of the gamma-crystallin family, is located in the water-richregion of eye lenses. The expressed C-terminal domain, gammaS-C, has beencrystallized and the 2.56 A X-ray structure determined. There are twodomains in the asymmetric unit which pair about a distorted twofold axis.One of the domains has an altered conformation in a highly conserved regionof the protein, the tyrosine corner. The distorted gammaS-C dimer ofdomains is compared with the highly symmetrical, equivalent recombinantdimer of C-terminal domains from gammaB- crystallin. Sequence changes closeto the interface, that distinguish gammaS from the other gamma-crystallins,are examined in order to evaluate their role in symmetrical domain pairing.     

Organized cell swimming motions in Bacillus subtilis colonies: patterns of short-lived whirls and jets

The swimming motions of cells within Bacillus subtilis colonies, as well as the associated fluid flows, were analyzed from video films produced during colony growth and expansion on wet agar surfaces. Individual cells in very wet dense populations moved at rates between 76 and 116 microm/s. Swimming cells were organized into patterns of whirls, each approximately 1,000 microm2, and jets of about 95 by 12 microm. Whirls and jets were short-lived, lasting only about 0.25 s. Patterns within given areas constantly repeated with a periodicity of approximately 1 s. Whirls of a given direction became disorganized and then re-formed, usually into whirls moving in the opposite direction. Pattern elements were also organized with respect to one another in the colony. Neighboring whirls usually turned in opposite directions. This correlation decreased as a function of distance between whirls. Fluid flows associated with whirls and jets were measured by observing the movement of marker latex spheres added to colonies. The average velocity of markers traveling in whirls was 19 microm/s, whereas those traveling in jets moved at 27 microm/s. The paths followed by markers were aligned with the direction of cell motion, suggesting that cells create flows moving with them into whirls and along jets. When colonies became dry, swimming motions ceased except in regions close to the periphery and in isolated islands where cells traveled in slow whirls at about 4 microm/s. The addition of water resulted in immediate though transient rapid swimming (> 80 microm/s) in characteristic whirl and jet patterns. The rate of swimming decreased to 13 microm/s within 2 min, however, as the water diffused into the agar. Organized swimming patterns were nevertheless preserved throughout this period. These findings show that cell swimming in colonies is highly organized.     

Aesthetic surgical training: the Lenox Hill model

This program enhances residency training in aesthetic surgery. It provides hands-on operating experience in a supervised hospital setting. Concerns of financial support and liability are addressed. Four chief residents from two university programs each spend 3 months conducting a "private" practice in a service population. A separate resident operative consent form unambiguously specifies the resident as the operating surgeon. Patients are derived from an advertised, free screening clinic every 3 months. The hospital has a special aesthetic surgical fee schedule for the residents. A resident operative fee is collected in support of resident salaries and insurance. An additional fee is collected on behalf of our anesthesiologists. During their 3 months the residents perform 30 to 40 operations as primary surgeon and 50 to 60 as the first assistant. Patient discontent, though rare, is resolved in conference with the patient, the resident, the attending surgeon, and the chief of section. Didactic training consists of monthly surgical conferences, journal club, and guest speaker presentations. Residents experience a practice setting by overseeing appointments to their clinic, booking operating room cases, and providing all paperwork for preadmission testing and certification, as well as fulfilling utilization and quality assurance requirements. They are responsible for their operative patients 24 hours a day, 7 days a week. The program is in its seventh year and its success is noted by continued full certification of the two participating university programs and absence of litigation.     

Extralenticular expression of the rodent betaB2-crystallin gene

A pregnant patient at 38 weeks' gestation developed symptoms of local anaesthetic toxicity following intravenous regional anaesthesia (IVRA) for hand surgery, using a standard dose of lignocaine. Reports suggest that a number of factors, both physiological and pharmacological, combine to increase the likelihood of local anaesthetic (LA) toxicity in pregnancy despite employment of a conventional "safe" IVRA technique. It is suggested that for IVRA, pregnant patients are premedicated with a benzodiazepine, the tourniquet time is increased and the concentration of LA is decreased to reduce the risks of LA toxicity.     

Application of polymerase chain reaction for the correlation of Salmonella serovars recovered from greyhound feces with their diet

The polymerase chain reaction was employed to correlate Salmonella serovars isolated from fecal material of greyhounds suffering from gastroenteritis with those isolated from the diet fed to the greyhounds prior to onset of diarrhea. Kennels around the Abilene, Kansas, area were contacted and supplied with materials needed to collect a portion of the diet each day. With the onset of diarrhea, the kennels were instructed to ship the fecal material and diet from the previous 10 days to the laboratory for testing. Forty-one fecal samples and corresponding diets were screened for Salmonella, Clostridium perfringens, Campylobacter jejuni, Staphylococcus aureus, Staphylococcus intermedius, and pathogenic (piliated) Escherichia coli by direct culture using standard procedures. The fecal material was also screened for coronavirus and parvovirus using electron microscopy. Thirty-five "normal" fecal samples were screened for all of the above mentioned microorganisms as a control. In addition, the fecal material was screened for E. coli verotoxins I and II and clostridial enterotoxins. A total of 61 Salmonella isolates were recovered from the 41 samples of feces and diet submitted for testing; 31 were recovered from the feces and 30 from the diet. Four Salmonella isolates were recovered from the normal fecal samples. Results obtained by PCR, plasmid profiles, antigenic analysis, and antibiogram profiles indicated that 16 of the 31 isolates recovered from the fecal material were the same strain as that recovered from the diet.