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Biomedical subjects

J Stoller

Publications and source records attributed to J Stoller.

17 recordsLinked to original sources
PubMed2006

[Peritonitis as a first manifestation of Neisseria type C meningitis].

A 15-year-old boy was first referred for a clinical presentation of revealed peritonitis. Abdominal endoscopy showed normal appendix but the presence of purulent peritoneal fluid. Antibiotics were immediately administered. Ten hours later clinical signs of meningitis occurred, and lumbar puncture was performed. CSF bacterial meningitis characteristics were present but no bacteria was observed. However Neisseria meningitidis type C was detected by direct peritoneal fluid examination and by 24(th) hour blood culture. Peritoneal and the CSF fluid culture were negative, but DNA analysis from peritoneal fluid was positive.

Adolescent↗
PubMed2000

A conserved role for H15-related T-box transcription factors in zebrafish and Drosophila heart formation.

T-box transcription factors are critical regulators of early embryonic development. We have characterized a novel zebrafish T-box transcription factor, hrT (H15-related T box) that is a close relative of Drosophila H15 and a recently identified human gene. We show that Drosophila H15 and zebrafish hrT are both expressed early during heart formation, in strong support of previous work postulating that vertebrate and arthropod hearts are homologous structures with conserved regulatory mechanisms. The timing and regulation of zebrafish hrT expression in anterior lateral plate mesoderm suggest a very early role for hrT in the differentiation of the cardiac precursors. hrT is coexpressed with gata4 and nkx2.5 not only in anterior lateral plate mesoderm but also in noncardiac mesoderm adjacent to the tail bud, suggesting that a conserved regulatory pathway links expression of these three genes in cardiac and noncardiac tissues. Finally, we analyzed hrT expression in pandora mutant embryos, since these have defects in many of the tissues that express hrT, including the heart. hrT expression is much reduced in the early heart fields of pandora mutants, whereas it is ectopically expressed subsequently. Using hrT expression as a marker, we describe a midline patterning defect in pandora affecting the anterior hindbrain and associated midline mesendodermal derivatives. We discuss the possibility that the cardiac ventricular defect previously described in pandora and the midline defects described here are related.

Amino Acid Sequence↗
PubMed2000

Peripheral nerve injury from intravenous cannulation: a case report.

The following is a case report of a patient who had an intravenous (i.v.) catheter inserted into her cephalic vein and thereafter sustained an injury to the superficial branch of the radial nerve. When an i.v. catheter penetrates a nerve, it can cause temporary or permanent damage. After sustaining an injury, a nerve will regenerate in an attempt to reconnect with the fibers it once innervated. Recovery from nerve damage may take only weeks or a year or more. Some patients, however, may sustain lifelong damage depending on the severity of the needle stick to the nerve. To avoid injury to peripheral nerves when inserting i.v. catheters, a few recommendations should be followed. First, if inserting an i.v. catheter in the cephalic vein, be conscious of the proximity of the superficial peripheral nerves. Second, if a paresthesia is elicited when inserting an i.v. catheter, withdraw the catheter immediately. Third, if a patient complains of paresthesias or numbness near the i.v. site, remove the i.v. catheter immediately. Fourth, limit the amount of probing after inserting the catheter into the skin. Finally, if nerve damage is suspected from a peripheral i.v. cannulation, consult a hand specialist promptly.

Catheterization, Peripheral↗
PubMed1998

Dynamic aspects concerned with the mechanism of separating motile sperm from nonmotile sperm, leukocytes, and debris with the use of high-density Percoll gradients.

OBJECTIVE: To investigate the dynamics and the efficacy of separating motile from nonmotile sperm with the use of Percoll gradients as a function of centrifugation time. DESIGN: In vitro laboratory experiments on human sperm. SETTING: Male Infertility Institute. PATIENT(S): Fresh sperm specimens collected from donors and patients. INTERVENTION(S): Aliquots of sperm specimens, spread on top of 40% and 80% Percoll layers in test tubes, were centrifuged for 5-60 minutes. MAIN OUTCOME MEASURE(S): After centrifugation, samples were aspirated from the bottom, interface, and top layers for microscopic analysis. RESULT(S): Within 5 minutes, only fast-moving sperm reached the bottom as a result of both centrifugation force and their own tail movements. From 10 minutes onward, nonmotile sperm, slowed down by Percoll, joined them and gradually reversed the separation process. Leukocytes, debris, and abnormal sperm remained in the upper levels and never reached the bottom. CONCLUSION(S): Separation of motile sperm with the use of Percoll gradients is strongly dependent on centrifugation time. The separation is the gap formed between down-swimming sperm, accelerated by centrifugation, and nonmotile sperm, decelerated by Percoll. This gap gradually disappears with extended spinning.

Cell Separation↗
PubMed1997

A double-blind, randomized study of three antimicrobial regimens in the prevention of infections after elective colorectal surgery.

The objective of this study was to assess the prophylactic efficacy of cefoxitin, ceftizoxime, and metronidazole-gentamicin in colorectal surgery. A double-blind, randomized prospective clinical trial design was used in a Canadian tertiary care teaching hospital. Patients were randomized to one of three treatment groups and received three doses of a study drug (30 min preoperative and 2 postoperative doses at 12 and 24 h). Cefoxitin and ceftizoxime were given as 1000-mg doses. Metronidazole-gentamicin was given as 500 mg of metronidazole plus 120 mg of gentamicin in a minibag. High-risk patients (bowel ischemia, diabetic, current steroid use, etc.) received 10 postoperative doses. Patients with infections, prior antibiotics, or study drug allergies were excluded. Over 30 months, 153 patients were enrolled. Thirty-one patients were excluded for protocol violations. Of the 122 evaluable patients (38 ceftizoxime, 45 metronidazole-gentamicin, 39 cefoxitin), there was no difference across groups regarding sex, age, weight, preoperative Apache II score, and prior history of bowel surgery. Groups were equivalent regarding surgeon, nursing unit, high-risk status (six ceftizoxime, seven metronidazole-gentamicin, seven cefoxitin), bowel preparation, and procedure (including blood loss, drains, organ injury, intraoperative complications). Clinically significant infection requiring systemic antibiotics (7-day hospital and 30-day follow-up) was identified in 0% of ceftizoxime, 15% of metronidazole-gentamicin, and 26% of cefoxitin receiving patients (p = 0.005). Mean ASEPSIS scores for each group were 2.3 (range 0-15) for ceftizoxime, 9.2 (range 0-45) for metronidazole-gentamicin, and 10.4 (range 0-75) for cefoxitin (p = 0.01). Ceftizoxime patients tended to have a shorter total hospital stay (12.2 days versus 19.7 days for cefoxitin versus 13.9 days for metronidazole-gentamicin; p = 0.04), although the procedure to discharge interval was not significantly different (p = 0.09). There was no difference in clinical outcome according to risk status. Anaerobic bacteria were observed more commonly in the ceftizoxime and cefoxitin groups, whereas enteric Gram-negative aerobes were observed most often in the metronidazole-gentamicin group. The study regimens were generally well tolerated. Drug costs were equivalent between ceftizoxime and cefoxitin and lowest with the metronidazole-gentamicin regimen. Ceftizoxime appears to be more effective for the prevention of infection in colorectal surgery than either cefoxitin or metronidazole-gentamicin in the dosage regimens studied.

Adult↗
PubMed1995

Evaluating the accuracy of different sperm counting chambers by performing strict counts of photographed beads.

PURPOSE: To suggest a method for evaluating the accuracy of different kinds of sperm counting chambers by eliminating errors concerned with human skills or semen properties. In this method, various concentrations were prepared from stocks of commercially available latex beads (Accu-beads, Hamilton-Thorn Research, Beverly, MA). Samples from identical preparations were loaded into different types of chambers, namely, hemocytometer (Neubauer, improved double, Superior Ltd, Germany), Makler (Sefi Medical Instruments, Haifa, Israel) and Horwell (Horwell Ltd, London, UK). Beads were counted by both direct microscopic observations and by strict scanning of their photographed images. RESULTS: In all cases, counts by direct observation were about 5% higher than strict counts of the same photographed beads. Counting photographed beads showed high reproducibility (average CV of 5.1%) between samples in the two wells of the hemocytometer. Counts of photographed beads, sampled from identical stocks, were on average slightly lower in the Makler chamber (20.7 x 10(6)/ml) and much higher in the Horwell chamber (47.4 x 10(6)/ml) than counts in the hemocytometer (21.5 x 10(6)/ml). Samples from three different batches of Accubeads revealed slight variation in counts between the batches and an average concentration of 11% above the number indicated on the commercial product. CONCLUSIONS; A technique that combined loading latex beads from identical stock into various chambers, proper covering of the tested samples and strict counting of photographed beads provided precise and reproducible results. By eliminating most errors related to human skills and semen properties, this method is suitable for evaluating the accuracy of counting chambers.

Equipment Design↗
PubMed1995

Inability of human sperm to change their orientation in response to external chemical stimuli.

OBJECTIVE: To investigate whether human sperm can respond to external chemical stimuli by orienting themselves toward chemoattractants or withdrawing from hostile environments. DESIGN: Controlled laboratory assays. SETTING: Normal human sperm and two other flagellated micro-organisms were exposed to various potential chemoattractant or chemorepellent substances. INTERVENTION: Human sperm, Euglena viridis, and Escherichia coli were exposed to various substances from the female reproductive system or to various toxic agents by placing them within tiny wells in a sealed minichamber. They were followed by microscopic observation and by intermittent photography. MAIN OUTCOME MEASURE: Images of photographed micro-organisms were analyzed for signs of attraction to or withdrawal from the test substances. RESULTS: Human sperm neither changed their orientation toward nor accumulated next to the well that contained cervical mucus, uterine cavity and follicular fluid, cumulus cells, or intact nonfertilized human eggs. Contrary to other micro-organisms that turned away from sources of hydrochloric acid, sodium hydroxide, ethanol, or glutaraldehyde, human sperm did not withdraw from these solutions. They swam along the ascending chemical gradient, facing ahead while becoming immobilized by these agents. CONCLUSION: It may be implied from the observation that they did not turn away from a hostile environment when expected to do so or turn toward chemoattractants that human sperm do not respond to external chemical stimuli and, most probably, chemotaxis between human sperm and ova in nature does not exist.

Animals↗
PubMed1993

Use of a sealed minichamber for direct observation and evaluation of the in vitro effect of cigarette smoke on sperm motility.

OBJECTIVE: To determine the in vitro effect of cigarette smoke on sperm motility and survival in an attempt to find a possible association with clinical studies that had pointed to the existence of such an effect in vivo. DESIGN: Laboratory experiments in which the effect of cigarette smoke on human sperm placed in a sealed minichamber was directly observed and determined by motion analysis. PATIENTS: High-quality fresh semen specimens were obtained from healthy donors and used for the experimental studies. INTERVENTIONS: Various doses of filtered and nonfiltered cigarette smoke, collected by an improvised manual smoking machine, were streamed at a rate of 2 mL/s into sealed chambers containing samples of washed spermatozoa. Evaluation of the changes in sperm motility was performed in real time by direct microscopical observation and repeated determinations by the multiple exposure photography technique until their complete immobilization. RESULTS: Streaming of 100 mL of cigarette smoke induced a dramatic drop in sperm motility, which caused sperm immobilization in about 15 minutes. This effect showed a clear dose-response relationship either with the amounts streamed or with the time during which sperm were exposed to cigarette smoke. The harmful effect was almost the same whether sperm were exposed to filtered or nonfiltered cigarette smoke. The role of carbon monoxide and hydrogen cyanide on these findings was studied separately, and it was shown that the inhibitory effect was not due to the presence of these two important components of cigarette smoke. CONCLUSIONS: The clear evidence of the in vitro harmful effect of crude cigarette smoke on sperm motility points to the possibility that in heavy smokers certain toxic agents may reach mature spermatozoa or their precursors via the blood stream and induce their harmful effect on sperm motility in vivo.

Carbon Monoxide↗
PubMed1993

Zidovudine dosage.

Explore the source record for details and available documents.

HIV Infections↗
PubMed1993

Investigation in real time of the effect of gravitation on human spermatozoa and their tendency to swim-up and swim-down.

To investigate in real time if and how natural gravity affects rates of swim-up and swim-down of human spermatozoa, samples of motile or immobilized spermatozoa in a sealed mini-chamber were placed vertically on a 90 degrees tilted microscope. The mode of their sedimentation, as well as the difference in the rate of their swimming up and down, were observed directly over 30 min and analysed from photomicrographs. Under the influence of natural gravity force, most immobilized spermatozoa turned their heads down in about 5 min and then sank slowly at an average speed of 0.2 mu/s. The number of motile spermatozoa that swam down was 5-6 times more than those swimming up. It can be implied that in spite of the mild force exerted by 1 g on suspended spermatozoa in comparison to the high g force obtained by centrifugation, the overall effect of gravity on the rate of swimming up or down becomes dominant. Gravity causes the sperm heads to turn downward after which the oriented spermatozoa continue to move down by their own tail movements, causing accumulation of motile spermatozoa at the bottom. This may explain why in some recent studies swim-down was superior to the swim-up procedure during sperm separation by self-migration.

Gravitation↗
PubMed1992

A new model for investigating in real-time the existence of chemotaxis in human spermatozoa.

OBJECTIVE: To suggest a new approach to the research of chemotaxis between various media and human spermatozoa to solve the riddle of its existence. DESIGN: Laboratory experiments in which chemotaxis between human spermatozoa and follicular fluid (FF) as well as N-formyl was investigated. SETTING: Male physiology laboratory and in vitro fertilization program unit. PATIENTS: Follicular fluid was collected from 15 patients and used either fresh or after storage at -5 degrees C for less than 2 weeks. High-quality semen specimens were obtained from normal donors and underwent one-step washing with Ham's F-10 solution (Biological Industries, Kibbutz Beth Haemek, Israel). TECHNIQUES: Assays were performed in real time by direct microscopical observation and quantitative determination of the disturbance in random movements of human spermatozoa caused by the tested media. Spermatozoa and tested media, including FF and N-formyl-Met-Leu-Phe were placed in a sealed minichamber and photographed with the aid of the multiple exposure photography technique. RESULTS: By analyzing photographed tracks of more than 80,000 moving spermatozoa, a physiologically insignificant deviation from randomness, corresponding to a 95% confidence interval of -0.57 +/- 0.46%, was found when spermatozoa swam along the concentration gradient of the tested media. The average velocity of spermatozoa swimming toward the test media was slightly lower (less than 5%) than that for spermatozoa swimming away, indicating, if anything, negative chemoattraction. CONCLUSIONS: Despite the high sensitivity of the model, neither natural FF nor synthetic N-formyl exerted any chemotaxis on human sperm. The advantages and potential use of this model for investigating chemotaxis by other biological and synthetic media are discussed.

Body Fluids↗
PubMed1989

Impact of new radiotherapy modalities on the surgical management of cancer of the esophagus and cardia.

At the Cancer Control Agency of British Columbia, 483 patients with cancer of the esophagus and cardia were seen from 1970-1980. Four hundred and one out of 483 (83%) had tumors larger than 5 cm (T2) and in 288/483 (60%) the disease had extended beyond the esophageal wall (T3). The overall 5-year survival rate was only 9% for all patients treated by external irradiation. The 5-year survival for a selected group having esophagectomy was 20%. Most patients died of persistent cancer at the primary site (83%); the cause of death was aspiration pneumonia (82%) due to obstruction caused by the persistent cancer. Our most recent experience using intracavitary irradiation either prior to or after external irradiation in 211 patients has been safe and simple and preliminary analysis of treatment results suggests that it has improved the therapeutic ratio. The analysis of quality of life at 6 months following therapy as it relates to performance status, swallowing ability, weight, and pain indicated significant improvement in all of these parameters. Of 171 patients, 33% were still alive at 1 year, 26% at 2 years, and 19% at 3 years following treatment. Of 43 patients suitable for preoperative irradiation, only 26 patients were actually resected and 19 of them are still alive with no evidence of disease, 8 to 30 months. The rationale and technical aspects of the combined treatment are described in detail. Treatment results, complications and an outline for future programs based on this experience are also described.

Body Weight↗
PubMedDate not supplied

Use of a sealed mini-chamber to investigate human sperm motility in real time under aerobic and anaerobic conditions.

To study the correlation between metabolism and motility, ejaculated human spermatozoa were washed in media containing glucose, pyruvate, and deoxyglucose in various combinations. Spermatozoa suspended in these media were incubated in sealed mini-chambers and subjected to aerobic or anaerobic conditions at 37 degrees C. The effect on the patterns of sperm motility was investigated in real time by direct observation and objective determination with the multiple exposure photography (MEP) method. The motility of spermatozoa incubated in media containing excess of glucose showed similar changes of motility quality with time, whether exposed to aerobic or anaerobic conditions, and in both cases motility lasted about 13 h. Motility of sperm incubated with pyruvate only was of a much lower quality, especially under anaerobic conditions, and in both circumstances lasted about 7 h. When glycolysis of fructose remnants was totally inhibited by deoxyglucose and sperm were incubated with pyruvate only, motility lasted for 2 h under aerobic conditions and only for about 1 h under anaerobic conditions. It is concluded that the main metabolic process that supplies energy for sperm motility is glycolysis, under both aerobic and anaerobic conditions. Oxidative respiration was less efficient as a source of energy for sperm motility. When glycolysis was inhibited and oxidative respiration was eliminated under anaerobic conditions, sperm motility lasted only for about 1 h, probably by using intracellular energy reserves.

Aerobiosis↗
PubMedDate not supplied

Balancing the perfect scorecard. Inquiry as intervention in physician practice management.

We describe how inquiry into several operational aspects of health care delivery in the Division of Medicine at the Cleveland Clinic Foundation improved clinical and administrative functions, demonstrating the principle that inquiry is intervention. The process of inquiry displays data on a "performance wheel" that summarizes several indicators, allowing easy comprehension of performance in various operational aspects and a visual appreciation of the interaction among these operational aspects.

Appointments and Schedules↗