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Biomedical subjects

M Reynolds

Publications and source records attributed to M Reynolds.

At least 55 records · Page 3Linked to original sources
PubMed1997

Neonatally wounded skin induces NGF-independent sensory neurite outgrowth in vitro.

An in vitro model was established to investigate factors underlying the sensory hyperinnervation of neonatal rat skin wounds that has been observed in vivo (Reynolds and Fitzgerald, J. Comp. Neurol. 358 (1995) 487-489). Explants of normal and wounded rat dorsal foot skin were co-cultured with explants of embryonic chick or newborn rat dorsal root ganglia for 24 h and the number of sensory neurites counted. Explants of skin surrounding a wound made at birth were taken 3 (P3) or 10 (P10) days later and compared with normal skin of the same age. In addition, explants were taken from adult skin wounded 3 and 10 days earlier. At P3, normal skin induced weak neurite outgrowth (mean 13.1 +/- 2.1 neurites per ganglion explant) but skin that had been wounded 3 days earlier, at birth, induced three times more neurite outgrowth (37.8 +/- 3.3). Ten days after wounding at birth, neurite outgrowth was still substantial (40.9 +/- 3.3) although at that age (P10), even normal skin stimulates substantial growth (37.4 +/- 2.9). Normal adult skin also stimulated neurite outgrowth (28.7 +/- 0.45) but this was not increased by wounding 3 or 10 days earlier, and this was enhanced 3 days but not 10 days after wounding. Anti-NGF (nerve growth factor) added to the culture medium blocked the constitutive neurite stimulating activity from normal P10 and adult skin but was ineffective in blocking the neurite stimulating activity produced by neonatal wounding. It is concluded that skin wounding at birth results in release of one or more sensory neurotrophic factors that stimulate rat and chick dorsal root ganglia neurite outgrowth for at least 10 days, but which do not include NGF.

Animals↗
PubMed1997

Intranasal midazolam in patients with status epilepticus.

The patient in status epilepticus presents many challenges to the emergency physician. IV access is frequently difficult to achieve, and prolonged attempts at access can jeopardize the patient and endanger the caregiver. We present two cases in which the administration of intranasal midazolam appeared to successfully terminate status epilepticus. No adverse effects were noted. Studies are needed to clarify the safety, optimal dosing, and clinical utility of this treatment modality.

Administration, Intranasal↗
PubMed1997

Pediatric oncology. Surgical and radiologic correlations.

Many aspects of surgical decision making related to the surgical evaluation and management of children with cancer depend on information gained from radiographic imaging and radiologic consultation. A brief review of the questions that surgeons ask the radiologist may aid the radiologist in focusing the consultation.

Abdominal Neoplasms↗
PubMed1996

Pancreatic blastomatous tumor in a child responding to therapy used for hepatoblastoma: case report and review of the literature.

A case is reported of a 7-year old girl diagnosed with initially inoperable metastatic embryonic pancreatic tumor, which showed a significant clinical response to chemotherapeutic agents commonly used to treat hepatoblastoma. This regimen was selected because certain histologic features of the tumor demonstrated characteristics seen in hepatic tissue. After two course of chemotherapy (cis-platinum and adriamycin), there was a significant reduction of the primary mass, and it was completely resected, although the tumor subsequently recurred in the metastatic, unoperated site. The embryological relationship between the tumor in this patient and hepatoblastoma, as well as the literature concerning treatment in pediatric pancreatoblastic tumors are reviewed. Complete eradication of tumor appears to be necessary for cure.

Antibiotics, Antineoplastic↗
PubMed1996

Intestinal bypass of the esophagus.

Esophageal replacement by a segment of isoperistaltic ileum with cecum or by transverse or left colon will allow near-normal swallowing for many years. The authors reviewed the course of 59 children who had bypass of their entire esophagus and of four whose distal esophagus was resected and replaced. The follow-up period ranges from 1 to 37 years; in 36 cases, it exceeds 5 years. Thirty children had caustic strictures and 25 had either isolated esophageal atresia or atresia with fistula. Two children with esophageal injury caused by foreign body ingestion and two with congenital strictures also required complete bypass. Four patients required resection and replacement of the distal esophagus only; two had acquired strictures from gastroesophageal reflux, one had varices, and one had a teratoma involving the esophagus. A retrosternal isoperistaltic ileocolic segment is our preference for complete esophageal replacement. Forty-eight patients underwent esophageal reconstruction with this procedure. The esophagus damaged by caustic ingestion was left in place in all patients, without any subsequent problem. The authors have not used the distal esophagus for anastomosis in patients with atresia, because this segment may be abnormal; and, in any case, an isoperistaltic cologastric anastomosis does not reflux. The right or left colon or jejunum was used in the other cases. Three children lost an interposed intestinal segment from necrosis even though the bowel appeared to be well vascularized at the end of the operation. Each patient had successful reconstruction using another type of interposition. An intrathoracic leak occurred in one infant. A cervical anastomotic leak developed in 11 children, and a stricture in 13. Strictures were more common in patients who had caustic burns. Three patients required surgery for adhesive intestinal obstruction. A redundant colon transplant with ulceration, and the herniation of an ileal segment into the pleural cavity with obstruction prompted reoperation in two other patients. There were two deaths early in the series, one of which was secondary to postoperative respiratory arrest. The other death occurred in a child who had a caustic pharyngeal burn and chronic aspiration. All patients were seen in our office recently, or they or their parents were interviewed by phone. All of them are taking all of their nutrition by mouth. Forty-three of the 61 survivors have had no difficulty with swallowing. One required reoperation to enlarge the thoracic inlet. Seventeen other have mild dysphagia that does not require treatment. The patients with esophageal atresia or atresia and fistula consistently have not grown as well as those who required replacement for an acquired condition or injury.

Burns, Chemical↗
PubMed1996

Monitoring of intrusions in post-traumatic stress order: a report of single case studies.

The effect of monitoring on frequency and duration of intrusions, and on reported symptomatology in patients with a diagnosis of post-traumatic stress disorder (PTSD) was investigated. Six patients were asked to monitor their intrusions over a period of two months. The patients were reassessed after completing the monitoring and followed up after three months. Four patients recovered and no longer met criteria for PTSD, one patient was still experiencing some symptoms, and one still met criteria for a diagnosis of PTSD.

Adult↗
PubMed1996

Treatment of pneumothorax in the patient with AIDS.

With the diagnosis of the adult immunodeficiency syndrome (AIDS), a patient's risk of sustaining a nontraumatic pneumothorax increases to 450 times that of the general population. The approach to pneumothorax that occurs in the patient with AIDS differs from the strategy that is used for spontaneous pneumothorax in immunocompetent young adults. The modifications in treatment are predicated on understanding the etiology of spontaneous lung collapse in the patient with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1995

Reorganization of central terminals of myelinated primary afferents in the rat dorsal horn following peripheral axotomy.

We have investigated the time course and extent to which peripheral nerve lesions cause a morphological reorganization of the central terminals of choleragenoid-horseradish peroxidase (B-HRP)-labelled primary afferent fibers in the mammalian dorsal horn. Choleragenoid-horseradish peroxidase is retrogradely transported by myelinated (A) sensory axons to laminae I, III, IV and V of the normal dorsal horn of the spinal cord, leaving lamina II unlabelled. We previously showed that peripheral axotomy results in the sprouting of numerous B-HRP-labelled large myelinated sensory axons into lamina II. We show here that this spread of B-HRP-labelled axons into lamina II is detectable at 1 week, maximal by 2 weeks and persists for over 6 months postlesion. By 9 months, however, B-HRP fibers no longer appear in lamina II. The sprouting into lamina II occurs whether regeneration is allowed (crush) or prevented (section with ligation), and does not reverse at times when peripheral fibers reinnervate the periphery. We also show that 15 times more synaptic terminals in lamina II are labelled by B-HRP 2 weeks after axotomy than in the normal. We interpret this as indicating that the sprouting fibers are making synaptic contacts with postsynaptic targets. This implies that A-fiber terminal reorganization is a prominent and long-lasting but not permanent feature of peripheral axotomy. We also provide evidence that this sprouting is the consequence of a combination of an atrophic loss of central synaptic terminals and the conditioning of the sensory neurons by peripheral axotomy. The sprouting of large sensory fibers into the spinal territory where postsynaptic targets usually receive only small afferent fiber input may bear on the intractable touch-evoked pain that can follow nerve injury.

Afferent Pathways↗
PubMed1995

Acute biliary pancreatitis. The roles of laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography.

Since January 1990, we have treated 113 patients for gallstone pancreatitis; 59 with laparoscopic cholecystectomy (LC), 50 with open cholecystectomy, and 4 with ERCP/sphincterotomy only. In the LC group, 47 had LC during the index admission and 12 underwent delayed LC. Fifty patients had open cholecystectomy, 47 during the index admission. ERCPs were performed in 43 of the 113 patients; CBD stones were identified in 19/43 (44%) and removed endoscopically in 18 (95%). The ERCP complication rate was 6.5%. In total, CBD stones were identified in 29/113 patients (26%). Patients who had imaging of the CBD within the first 4 days from onset of symptoms were more likely to have stones identified than were those patients who were studied after 5 days. Recurrent pancreatitis occurred in in five of 11 patients (45%) who had a > or = 30-day delay to definitive treatment. We conclude that LC can be safely performed in most patients during the index admission for gallstone pancreatitis. This policy should reduce the 30-50% risk of recurrent pancreatitis associated with a delayed operation. ERCP is a helpful adjunct for CBD stones.

Acute Disease↗
PubMed1995

Peritoneal host defenses are less impaired by laparoscopy than by open operation.

There is a growing body of evidence that laparoscopic surgery is physiologically less injurious than open surgery. We hypothesized that the open technique results in a greater impairment of peritoneal and systemic defense mechanisms than does the laparoscopic technique. Nissen fundoplication, standardized in technique and duration, was performed in 16 pigs. The procedure was performed through a standard midline incision (OPEN, n = 8) or with laparoscopic technique and CO2 pneumoperitoneum (LAP, n = 8). The peritoneal cavity was instilled with 400 cc of normal saline, either alone (not contamined, n = 8) or containing 10(9) E. coli/ml (contaminated, n = 8). Quantitative cultures, cell count, and flow cytometry were performed on blood and peritoneal fluid samples obtained at timed intervals. We found that host defense processes were better preserved after LAP than by OPEN surgery. Peritoneal and systemic monocyte class II antigen expression, and serum tumor necrosis factor-alpha activity was greater in the OPEN group compared with the LAP group, but peritoneal bacterial clearance was more efficient in the LAP group. These data may illustrate a potential benefit of laparoscopic surgery in cases of peritoneal contamination.

Animals↗
PubMed1994

(-)-Norcocaine.

The title compound, [2R,3S-(2 beta,3 beta)]-methyl 3-(benzoyloxy)-8-azabicyclo[3.2.1]octane-2-carboxylate, C16H19NO4, is a metabolite of the tropane alkaloid cocaine. The molecule crystallized as the free base with the piperidine ring in a chair conformation. The tropane ring system and its methoxycarbonyl and benzoyl groups are rigid; only rotational flexibility is allowed in the conformation of the substituents.

Cocaine↗
PubMed1994

Structural study of a DNA.RNA hybrid duplex with a chiral phosphorothioate moiety by NMR: extraction of distance and torsion angle constraints and imino proton exchange rates.

The solution structure of the thiophosphate-modified DNA.RNA hybrid duplex d(GCTATAApsTGG).r(CCAUUAUAGC) has been studied by NMR. Two samples with pure stereochemistry in the modified phosphate have been investigated. Two-dimensional NMR (2D NMR) methods have been applied to assign nearly all the resonances in both duplexes. Scalar coupling constants have been determined by comparing quantitative simulations with experimental double-quantum filtered COSY (DQF-COSY) cross-peaks. More than 300 distance constraints have been obtained from two-dimensional nuclear Overhauser spectroscopy (2D NOE) spectra recorded in D2O and H2O by using a complete relaxation matrix analysis as implemented in the program MARDIGRAS. This hybrid duplex presents a heteronomous structure. Riboses in the RNA strand are found in a N-type conformation typical of the A-form family as shown by the lack of H1'-H2' cross-peaks in DQF-COSY spectra and confirmed by the measured interproton distances. In contrast, the DNA strand adopts a different conformation with sugar puckers partially in the S-type domain, which is not in agreement with the A-family of structures. Coupling constants in deoxyriboses are not consistent with any single sugar conformation. Therefore, sugar pucker pseudorotation parameters are calculated according to a two-state dynamic equilibrium between N- and S-type conformers. In general, the population of major S conformer is lower than in double-stranded DNA duplexes, indicating that hybrid duplexes may be more flexible than pure DNA or RNA. The only differences observed in the spectra between the two stereoisomers studied originate from resonances of protons located near the modified phosphate. No significant differences in interproton distance have been detected, and only a slight difference of sugar pucker in the 5' neighbor has been found. The sulfur atom appears to be well-accommodated without further changes in the structure of the hybrid.

Base Sequence↗
PubMed1994

Thought suppression and smoking cessation.

Deliberate suppression of intrusive thoughts has previously been shown to be associated with higher levels of intrusion compared to monitoring without suppression. In an attempt to apply this paradigm to people attempting smoking reduction and cessation, it was demonstrated that intrusive thoughts about smoking occur frequently. Subjects reported difficulty in controlling smoking related intrusions, and ratings indicated that all subjects made attempts to suppress them. In an experimental study, instructions to suppress were associated with increased frequency of intrusion compared to the control (mention) condition. A simple distracting task was highly effective in reducing intrusion frequency to below the levels obtained in the control condition, and intrusions remained significantly lower during the second (non-suppression) period.

Adult↗
PubMed1994

A structured literature review for risk assessment: EMF and human health risk.

The volume of publications on any given topic makes it difficult to select an appropriate subset of publications for review by an expert panel. This paper proposes a method for selecting a subset using a protocol that attempts to order publications based upon good research methods. The protocol was followed by graduate students with no expert knowledge of the area they were reviewing. They reduced 11730 articles on the topic of EMF and Health risk to 68 articles that were reviewed by an expert panel. The interrater reliability was 96% and 94% of the relevant articles were captured by this process.

Animals↗
PubMed1994

The teaching of empathy for high school and college students: testing Rogerian methods with the Interpersonal Reactivity Index.

The teachability of empathy is discussed with particular regard to developmental issues. One hundred and four high school and college students were administered Davis's (1980) Interpersonal Reactivity Index (IRI) both before and after a standard course of Rogerian-based peer facilitation skills training. The IRI offers four independent subscales which measure the cognitive and affective components of empathy. Statistically significant findings indicate greater developmental readiness for learning empathic communication in the college sample, particularly for subscales measuring Empathic Concern and Perspective Taking. A group of untrained college students taking a course in behavioral psychology showed no progress on any IRI subscales. Although college females began with higher empathy scores, both genders were equally teachable. Implications for prevention and counseling readiness are discussed, along with suggestions for future research.

Adolescent↗