Accommodation responses to stimuli in cone contrast space

The aim was to identify the cone contributions and pathways for reflex accommodation. Twelve illumination conditions were used to test specified locations in cone-contrast space. Accommodation was monitored continuously in a Badal optometer while the grating stimulus (2.2 c/d sine-wave; 0.27 modulation) moved sinusoidally (0.195 Hz) towards and away from the eye from a mean position of 2.00 D (+/-1.00 D). Mean accommodation level and dynamic gain and phase at 0.195 Hz were calculated. Mean accommodation level varied significantly when the long- and middle-wavelength cone contrast ratio was altered in both the luminance and chromatic quadrants of cone-contrast space. This experiment indicates that L- and M-cones contribute to luminance and chromatic signals that produce the accommodation response, most likely through magno-cellular and parvo-cellular pathways, respectively. The L:M cone weighting to the luminance pathway that mediates accommodation is 1.63:1. The amplitude and direction of the response depends on changes in chromatic contrast and luminance contrast signals that result from longitudinal chromatic aberration and defocus of the image.     

Failure of erythromycin to eliminate airway colonization with <Emphasis Type="Italic">ureaplasma urealyticum</Emphasis>in very low birth weight infants

Background  

Airway colonization of mechanically ventilated very low birth weight infants (birth weight < 1500 grams) by Ureaplasma urealyticum (Uu) is associated with an increased risk of bronchopulmonary dysplasia (BPD). While Uu is sensitive to erythromycin in vitro, the efficacy of intravenous (IV) erythromycin to eliminate Uu from the airways has not been studied.     

Relationship between zona pellucida-induced acrosome reaction,sperm morphology,sperm-zona pellucida binding,and in vitro fertilization

OBJECTIVE: To evaluate the possible relationships between sperm morphology, acrosome responsiveness to solubilized human zona pellucida, and sperm-zona binding potential among [1] consecutive andrology referrals and [2] randomly selected in vitro fertilization (IVF) cases. DESIGN: Prospective analytical study. SETTING: Academic training hospital.Randomly selected couples consulting for infertility. INTERVENTION(S): Acrosome reaction response to solubilized human zona pellucida was recorded. MAIN OUTCOME MEASURE(S): We determined the difference in the percentage of sperm that acrosome reacted after exposure to solubilized zona pellucida and spontaneous acrosome reaction. The results were expressed as percentage zona induced acrosome reaction (ZIAR). RESULT(S): Data were analyzed using correlation coefficients (r) and receiver operator characteristics (ROC curve analyses). The ROC curve analyses indicated ZIAR to be a sensitive indicator for fertilization failure during IVF therapy, with sensitivity and specificity of 81% and 75%, respectively. For andrology referrals, a positive and statistically significant correlation existed between ZIAR data and sperm morphology (r = 0.65) and sperm-zona binding (r = 0.57). CONCLUSION(S): ZIAR results provide further information regarding dysfunctional sperm and can be used as an additional diagnostic test. Our results predicted fertilization failure during IVF treatment.     

Anaerobiospirillum succiniciproducens bacteraemia

This report describes a case of bacteraemia caused by Anaerobiospirillum succiniciproducens. Anaerobiospirillum succiniciproducens is a rare cause of bacteraemia in humans, and when encountered usually occurs in immunocompromised patients. The organism is an anaerobic, spiral shaped, Gram negative bacillus with bipolar tufts of flagella. In this report, the morphology, with special reference to electron microscopic features, culture characteristics, and antimicrobial susceptibility are described.     

S-adenosylhomocysteine,but not homocysteine,is toxic to yeast lacking cystathionine beta-synthase

Elevated plasma homocysteine is associated with a variety of diseases in humans including coronary heart disease, stroke, peripheral vascular disease, and birth defects. However, the mechanism by which plasma homocysteine affects cells is unknown. We have examined the growth of isogenic wild-type and cystathionine beta-synthase (CBS) deficient yeast in response to homocysteine and its immediate metabolic precursor, S-adenosylhomocysteine (SAH). CBS deficient yeast export significantly more homocysteine into the media than wild-type yeast and have elevated internal pools of homocysteine and SAH. We found that 5 mM homocysteine added to the media had very little effect on the growth of wild-type or CBS deficient yeast, although intracellular homocysteine concentrations increased five- to tenfold. In contrast, as little as 25 microM S-adenosylhomocysteine inhibited the growth of CBS deficient yeast, but had no effect on wild-type yeast. Measurements of the intracellular S-adenosylmethionine (SAM) and SAH indicate that CBS deficient yeast contain reduced SAM/SAH ratios relative to wild-type, and this ratio is further reduced by adding SAH to the media. Growth inhibition by SAH in CBS deficient yeast can be totally reversed by addition of SAM to the media, indicating that the ratio and not absolute level is critical for cell growth. These results suggest that CBS plays a key role in the regulation of the SAM/SAH ratio inside cells and that excessive perturbations of this ratio can inhibit growth. We hypothesize that elevated extracellular homocysteine present in humans may reflect an altered intracellular SAM/SAH ratio and that this may be related to disease pathogenesis.     

Evaluation of the performance of general emergency physicians in pediatric emergencies: Obstructive airway diseases,seizures, and trauma

BACKGROUND: In the Lübeck region, as is usual in Germany, hospital-based emergency physicians are called for outside emergencies. They evaluate and stabilize patients and transfer them to hospital facilities of their choice (no emergency department system). These physicians are mainly anesthesiologists, surgeons, and internists-not pediatricians. Numerous quality management studies have shown an overall excellent performance of this system, but it has not been evaluated for pediatric emergencies. PATIENTS AND METHODS: In a prospective, observational study conducted over a 1-year period, all pediatric emergencies (patient age < 15 y) treated by the emergency physician service were studied. A syllabus with standards of care for children with trauma, obstructive airway disease, and seizures was distributed. In accordance with this syllabus, the actions taken were documented by the emergency physicians, and the cases were documented as life threatening or not and were classified as "trauma," "obstructive airway disease," "seizures," or "other" by the admitting pediatric intensivists and surgeons. The admitting attending physician compared these data and evaluated whether the standard management required by the syllabus was followed. RESULTS: A total of 422 pediatric cases out of 11,605 emergencies (3.5%) were recorded (147 [34.8%] trauma patients, 41 [9.7%] patients with obstructive airway disease, and 108 [25.6%] patients with seizures). Of the pediatric patients, 20.5% had life-threatening conditions; three children died before arrival, and the others required treatment in the intensive care unit. In 25% of trauma patients, deficiencies in primary treatment were observed: no documentation of neurologic status in 10.6%, no cervical immobilization in 15% of head trauma patients, and no adequate analgesia in 7%. In 25% of seizure patients, neurologic status was not documented, although treatment was in accordance with the standard of care. The worst results were observed in infants with obstructive airway disease: no documentation of oxygen saturation in 71.4%, no oxygen therapy despite hypoxemia in seven of 12 patients, and overall therapy not in accordance with the standard of care in 50%. CONCLUSIONS: The high quality of the emergency physician service documented for adults is not reproduced in the pediatric population. Trauma and seizures with similarities to adult cases are handled in a fair manner. However, the most important pediatric diagnostic entity of obstructive airway disease is often not treated adequately. Intensified educational programs for emergency physicians are warranted.     

Pseudo-renal failure following the delayed diagnosis of bladder perforation after diagnostic laparoscopy

We present a case of bladder injury as a complication of gynaecological laparoscopic surgery. A young female presented with peritonitis, an acute systemic inflammatory response and biochemical features of acute renal failure secondary to urinary peritonitis. Laparotomy with drainage of urine from the peritoneal cavity and repair of the bladder perforation resulted in rapid resolution of the biochemical abnormalities.