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D B Jones

Publications and source records attributed to D B Jones.

At least 73 records · Page 4Linked to original sources
PubMed1998

Endoscopic axillary lymph node dissection: an experimental study in human cadavers.

BACKGROUND: The role of axillary lymph node dissection in the staging of patients with breast carcinoma is currently under evaluation. As a result of recent advances in minimally invasive techniques, an endoscopic approach to axillary lymph node dissection may be an attractive alternative to lymphadenectomy performed via a standard "open" axillary incision. The purpose of the present study was to evaluate the technical feasibility and safety of such an approach in human cadavers. STUDY DESIGN: Twelve axillary dissections (right in seven, left in five) were performed in seven cadavers. A 2.5-cm incision was made along the lateral chest wall 12 cm inferior to the apex of the axilla. The subcutaneous axillary space was expanded with a balloon dissector, and exposure was maintained with a prototype external lift device. Endoscopic dissection was performed with three or four 5-mm ports inserted into this space. Histologic analysis was performed to document the number of lymph nodes removed. RESULTS: The mean dissection time for endoscopic axillary lymphadenectomy was 56.7+/-19 minutes (range, 30-90 minutes). Structures visualized endoscopically included the axillary vein (12 of 12 patients), the long thoracic nerve (12 of 12 patients), the thoracodorsal nerve (10 of 12 patients), and the intercostobrachial nerve (11 of 12 patients). An average of 9.9+/-7.2 lymph nodes (range, 2-22 nodes) was removed from each axilla. Open exploration of the axilla after the endoscopic dissection confirmed no injuries to any neurovascular structures. Residual lymph nodes were removed from the axilla in 7 of 12 dissections (58%; average, 4.2+/-4.0 nodes per specimen). CONCLUSIONS: These results suggest that endoscopic axillary dissection is feasible with currently available technology. Clinical trials in patients with breast carcinoma may be warranted to evaluate this technique further.

Axilla↗
PubMed1998

Attachment kinetics, proliferation rates and vinculin assembly of bovine osteoblasts cultured on different pre-coated artificial substrates.

Primary bovine osteoblasts were used to study in-vitro effects of attachment on vinculin assembly in cells cultured on various artificial substrates. Materials coated with fibronectin and bovine serum albumin (BSA) as well as untreated materials (tissue culture polystyrene and Aclar foils) were chosen to investigate substrate-dependent proliferation during the first 3 days of culture. Proliferation was highest on fibronectin-coated substrates, followed by BSA-coated and untreated substrates. During the first 24 h of cultivation, cell attachment kinetics revealed no significant difference between the various substrates. After 24 h detachment rates obtained by calcium depletion with ethylenediaminetetraacetic acid were highest on uncoated materials, followed by BSA- and fibronectin-coated substrates. Phase contrast microscopy revealed typical osteoblast morphology after cell adhesion for 24 h. The dynamic attachment process was concomitant with the reassembly of vinculin into streak-like focal contacts clustered on the ventral side of cells. The kinetics of vinculin reassembly were independent of the underlying coating. Thus, fibronectin coating of artificial substrates increased the attachment strength and proliferation rate of osteoblasts. While the reassembly of vinculin in focal contacts seems to be a prerequisite of osteoblast attachment in vitro, it does not seem to have profound effects on the subsequent cell behaviour on artificial substrates.

Journal Article↗
PubMed1998

Extending the limits: minimally invasive surgery.

Minimally invasive technology is being applied to an increasing number of surgical procedures. It remains to be seen which techniques will eventually become a 'gold standard' as has the laparoscopic cholecystectomy, and which will fall by the wayside. In the meantime, anesthesiologists must be aware of the unique requirements and complications of laparoscopic surgery.

Journal Article↗
PubMed1998

Staging of oesophageal carcinoma by endoscopic ultrasound: preliminary experience.

BACKGROUND: Endoscopic ultrasound (EUS) is a relatively recent imaging modality that is capable of visualizing oesophageal tissue layers and para-oesophageal structures. Current pre-operative staging of oesophageal cancer is less than satisfactory, and a modality which may improve pre-operative staging, thus allowing a more rational approach to choice of treatment, may be a welcome addition to current techniques. The purpose of the present study was to evaluate the accuracy of EUS in the staging of oesophageal carcinoma in a consecutive cohort of patients. METHODS: Forty-three patients with oesophageal cancer were prospectively staged with EUS using the radial scanning Olympus EUM-3 echo-endoscope. In the 28 patients who underwent surgery EUS staging was correlated with operative and histological findings to evaluate the EUS accuracy rate of assessing tumour depth (T stage), and the presence of nodal involvement (N stage) using internationally accepted TNM staging criteria. RESULTS: Endoscopic ultrasound accuracy rates for overall T-staging was 61% whereas that of N-staging was 75%. The overall TNM pathological staging was 75% accurate by EUS. CONCLUSIONS: Compared to published literature figures for oesophageal staging by computed tomography scanning (39-54%) these results demonstrate that EUS has a reasonable accuracy rate for staging. Endoscopic ultrasound may prove to be a useful additional modality in the management of oesophageal cancer.

Adenocarcinoma↗
PubMed1998

Immunophenotypic characterization of stromal cells in aspirated human bone marrow samples.

The presence of stromal cells was investigated in aspirated bone marrow prepared by the same method as that used for the initiation of human long-term bone marrow culture (hLTBMC). In previous studies, we performed immunocytochemical staining of cytocentrifuge cell preparations using a panel of antibodies with which we characterized stromal cell populations in hLTBMC. This approach allowed morphological as well as immunophenotypic assessment of cells of interest. Morphologically distinctive cell populations expressing vascular cell adhesion molecule-1 and low-affinity nerve growth factor receptor (NGFR) were observed to be present, but no cells expressing alpha-smooth muscle actin were found. Few macrophages were present, consistent with the origin of hLTBMC stroma-adherent macrophages from monocytes and their precursor cells rather than from mature macrophages among the culture-initiating cells. In the absence of double immunostaining, it was not possible to deduce whether CD34+ cells, which were present in varying numbers in the cytocentrifuge preparations, included stromal as well as primitive hematopoietic cells. In addition to single cells, multicellular tissue fragments containing a variety of stromal cell types were detected in many samples. Their presence raises the possibility that at least some components of hLTBMC stroma may arise by explant growth from complex tissue fragments containing vascular and fibroblastic elements. Overall, our results indicate that demonstration of a variety of stroma-associated antigens, in particular NGFR, provides a useful new tool for identifying stromal elements in aspirated bone marrow.

Actins↗
PubMed1997

Acute and chronic conjunctivitis due to over-the-counter ophthalmic decongestants.

OBJECTIVE: To describe patterns of conjunctivitis caused by ophthalmic decongestants. DESIGN: Case series. SETTING: Outpatient eye clinic. PATIENTS: We selected patients with conjunctival inflammation who were using nonprescription decongestant eyedrops, who had no other cause for conjunctivitis, and whose conditions improved after discontinuing the incriminated preparations. MAIN OUTCOME MEASURES: Clinical characteristics of conjunctival inflammation and time to resolution of symptoms and signs after discontinuing the use of eyedrops. RESULTS: Seventy patients (137 eyes) were identified. Preparations containing the vasoconstrictors naphazoline, tetrahydrozoline, or phenylephrine were associated with 3 clinical patterns of conjunctivitis: conjunctival hyperemia (50 cases), follicular conjunctivitis (17 cases), and eczematoid blepharoconjunctivitis (3 cases). Decongestants were used daily for a median of 3 years (range, 8 hours to 20 years) prior to presentation. The median time to resolution of symptoms and signs was 4 weeks (range, 1-24 weeks), and patients remained asymptomatic for a median follow-up of 6 months (range, 0-12 years). CONCLUSION: Nonprescription decongestant eyedrops can produce acute and chronic forms of conjunctivitis by pharmacological, toxic, and allergic mechanisms. Once recognized, conjunctival inflammation often takes several weeks to resolve.

Acute Disease↗
PubMed1997

Surgical management of calcinosis cutis universalis in systemic lupus erythematosus.

Calcinosis cutis is common in several connective tissue diseases but rare in systemic lupus erythematosus (SLE). A 43-year-old woman with a 12-year history of SLE who presented with calcinosis cutis at the time of SLE diagnosis developed a large, ulcerated, draining mass on her left hip. The lesion was excised and skin was grafted, with an excellent early result. The clinical variants and mechanisms of ectopic calcification are discussed, as well as the proposed medical therapies for calcinosis cutis.

Adult↗
PubMed1997

Laparoscopic pancreaticoduodenectomy in the porcine model.

BACKGROUND: Minimally invasive techniques offer theoretical advantages for treating resectable periampullary neoplasms. Laparoscopic pancreaticoduodenectomy (LPD) was first reported in 1992 and has been performed clinically despite lack of animal data to support the operation. The purpose of this study was to develop LPD in an acute porcine model and to assess safety and efficacy before considering clinical trials. METHODS: LPD was initiated in six domestic pigs under general anesthesia. Once pneumoperitoneum was created, five 10-mm access ports were placed (one central and two in each flank). After cholecystectomy, the duodenum was mobilized and the proximal jejunum was divided distal to the ligament of Treitz. The neck of the pancreas was separated from the superior mesenteric vein, and the midstomach was divided by a stapler. Pancreaticojejunostomy (PJ), choledochojejunostomy (CDJ), and gastrojejunostomy (GJ) were performed using interrupted sutures. The animals were immediately sacrificed and the operative site was examined. RESULTS: LPD was aborted in three animals due to complications: intestinal perforation with fecal contamination (one) and prolonged resection time >/= 2.5 h (two). LPD was completed in three animals (operative time ranged from 5.0 to 7.5 h, blood loss < 200 cc); however, at sacrifice one PJ and two CDJs had small posterior leaks. The efferent loop of the GJ was narrowed by the staple line in one pig. All animals had extensive ecchymosis of the jejunal serosa due to excessive manipulation. CONCLUSION: Despite a significant number of anastomotic leaks in the immediate postoperative period, laparoscopic pancreaticoduodenectomy is feasible in a porcine model. Further studies and technical development are necessary before laparoscopic pancreatic resection can be performed on a more widespread basis.

Anastomosis, Surgical↗
PubMed1997

Infectious crystalline keratopathy caused by gram-negative bacteria.

PURPOSE: To identify the characteristics and outcomes of infectious crystalline keratopathy caused by gram-negative bacteria. METHODS: We reviewed all patients treated at a university eye center for infectious crystalline keratopathy from 1978 through 1995 and performed a nested case-comparison study by comparing patients with keratitis caused by gram-negative rods and those with keratitis caused by gram-positive cocci. RESULTS: Eighteen patients (mean age +/- SD, 59 +/- 17 years) displayed unilateral culture-positive infectious crystalline keratopathy. Among 18 eyes with crystalline keratopathy, five occurrences (28%) were caused by gram-negative rods (Acinetobacter lwoffi, Citrobacter koseri, Enterobacter aerogenes, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia), 10 (55%) were caused primarily by gram-positive cocci, and three (17%) were caused primarily by yeasts. Four cases grew two different isolates. No significant difference in predisposing factors, clinical appearance, or visual outcome was found between infections caused by gram-negative bacteria and those caused by gram-positive bacteria. CONCLUSIONS: Gram-negative bacteria can cause infectious crystalline keratopathy but have no distinguishing features from infectious crystalline keratopathy caused by streptococci and other gram-positive bacteria. Appropriate laboratory evaluation is therefore necessary to guide specific antimicrobial therapy.

Aged↗
PubMed1997

Implantation of colon cancer at trocar sites is increased by low pressure pneumoperitoneum.

BACKGROUND: The purpose of this study was to determine the effect of pneumoperitoneum on the implantation of tumor at trocar sites. METHODS: GW-39 human colon cancer cell suspension (0.5 ml of 2.5% v/v) was injected into the peritoneal cavity of golden Syrian hamsters through a 1 cm midline incision. Four 5 mm trocars were inserted through the anterior abdominal wall, and the midline incision was then closed. The animals were randomized to receive pneumoperitoneum (n = 62) or no pneumoperitoneum (n = 60) for 10 minutes. Tumor implantations at trocar sites and midline wound incisions were documented grossly and histologically 8 weeks later. RESULTS: Tumor was identified in 86% (49 of 57) of control animals and 95% (52 of 55) of the experimental group (p = 0.20). Implants increased with pneumoperitoneum at the midline incision from 44% to 71% (p < 0.01) and at trocar sites from 41% to 64% (p < 0.00001). CONCLUSIONS: Pneumoperitoneum significantly increased tumor implantation at trocar sites and midline incisions.

Animals↗
PubMed1997

Experimental development of an endoscopic approach to neck exploration and parathyroidectomy.

BACKGROUND: Recent advances in minimally invasive surgical technology have the potential to lead to new applications outside body cavities. The purpose of the present study was to develop techniques for obtaining endoscopic exposure and access to the pretracheal space in the neck with the goal of performing neck exploration and parathyroidectomy and to evaluate the safety and efficacy of such an approach experimentally. METHODS: The technique for endoscopic neck exploration was developed in eight adult mongrel dogs and was further evaluated in a survival dog model and in human cadavers. The pretracheal space was accessed by a 2.5 cm midline incision in the lower neck. This space was expanded with a balloon dissector, and exposure was maintained with an external lift device. A 5 or 10/12 mm midline port and two to four lateral 5 mm cervical ports were placed, and dissection was carried out with pediatric endoscopic instruments and an ultrasonic coagulator. Excised parathyroid tissue was verified histologically. RESULTS: Two-gland parathyroidectomy was successfully completed in five of six dogs; inadequate exposure led to a failed procedure in one animal. Mean operative time was 130 +/- 6 minutes, and there were no operative complications. Serum calcium levels did not change significantly after operation (p = not significant). At autopsy, approximately 20 ml of clear sterile fluid was present in the pretracheal space of every dog. In five human cadavers mean dissection time for attempted four-gland parathyroidectomy was 69 +/- 38 minutes (range, 45 to 135 minutes). Four of four parathyroids were identified and removed in two patients, three of three parathyroids in one patient, three of four parathyroids in one patient, and two of four parathyroids in one patient. CONCLUSIONS: Parathyroidectomy may be performed safely and reliably in an animal model with minimally invasive techniques that can be applied to parathyroid dissection in human cadavers. These results suggest that an endoscopic approach to neck exploration and parathyroidectomy is potentially feasible and may warrant further study in clinical trials.

Animals↗
PubMed1997

[Schnyder corneal dystrophy and juvenile, systemic hypercholesteremia].

BACKGROUND: Central crystalline dystrophy of Schnyder is characterized by the deposition of unesterified cholesterol crystals and lipids in the central and paracentral corneal stroma. Classically, this disease has been described as autosomal dominantly inherited and non-progressive with cholesterol deposits found in the anterior one third of the cornea. In recent years, however, rare sporadic cases and individuals with progressive, panstromal Schnyder's dystrophy have been described. Furthermore, an association has been made between some patients with Schnyder's dystrophy and a region on the coast in southwest Finland. Among the stromal dystrophies, this disease is unique with its occasional association with genu valgum and systemic hyperlipidemia. The role of high serum cholesterol in the pathogenesis of this disorder is still unclear. PATIENT: A ten-year-old white male presented with a one year history of ocular irritation made worse by bright sunlight. His past medical history was significant only for attention deficit disorder for which he received methylphenidate. A brother died at four months of age secondary to an unexplained cardiac abnormality. The ocular examinations of the patient's mother and father were normal and no history of eye disease among the grandparents could be elicited. The patient's visual acuity was 20/20 +2 in the right eye and 20/15 -3 in the left eye. The external examination showed no xanthelasmas. Slit-lamp biomicroscopy revealed bilateral ring-shaped corneal opacities extending into the midperiphery but sparing the limbal zone. The ring was composed of a fine, lacy garland of crystals present primarily in the anterior aspect of the stroma just beneath Bowman's membrane. The anterior chamber and iris showed no signs of inflammation. Intraocular pressures were 20 mm Hg and the ocular examination was otherwise unremarkable. Physical exam demonstrated no genu valgum. Blood testing showed a total cholesterol of 201 mg/dl with a low density lipoprotein cholesterol (LDL-C) of 156 mg/dl. Retesting four months later revealed a total cholesterol level of 245 mg/dl and an LDL-C of 192 mg/dl. The patient was referred to the pediatric gastroenterology service where he was put on diet therapy for further management of his hypercholesterolemia. CONCLUSIONS: This case appears to represent one of the rare sporadic examples of Schnyder's corneal dystrophy. The patient's family history is negative for ocular problems and the parents deny any Scandinavian ancestry. This patient is also unique for his presentation with ocular irritation. Most patients with Schnyder's dystrophy are initially seen for diagnosis of asymptomatic cloudy corneas or for gradual, painless loss of vision although glare in bright sunlight is noted by some individuals. Perhaps the most significant finding concerning this patient are his serum cholesterol levels. The association between total and LDL cholesterol and atherosclerotic vascular disease are well known and the literature suggests that regression of coronary artery disease is possible with aggressive treatment of hypercholesterolemia. Intervention in children should be considered if total cholesterol exceeds 170 mg/dl or LDL-C exceeds 110 mg/dl. Thus, early detection may eliminate significant morbidity and mortality. We therefore advocate evaluating all patients with Schnyder's corneal dystrophy and their immediate family members for systemic hypercholesterolemia.

Child↗
PubMed1997

Precipitation of overt encephalopathy in the portacaval shunted rat: towards the development of an adequate model of chronic portal systemic encephalopathy.

OBJECTIVE: To assess the feasibility of developing a model of overt portal-systemic encephalopathy (PSE) in rats with a surgically constructed portacaval anastomosis (PCA). DESIGN: The ability of increasing the load of nitrogenous substances in the gastrointestinal tract and/or further decreasing hepatocellular function to induce overt encephalopathy in rats with a PCA was determined. METHODS: The load of nitrogenous substances in the gastrointestinal tract was increased by feeding a pure horse-meat diet or by gavaging with blood. Partial hepatectomy and the induction of cirrhosis were used to decrease hepatocellular function further. The severity of encephalopathy was assessed using a neurobehavioural scale. RESULTS: Overt encephalopathy was not induced in rats by a PCA alone, by a PCA plus a horse-meat diet, by a PCA plus induction of cirrhosis, or by a PCA plus a 50% hepatectomy. Predominantly mild, but overt, encephalopathy was induced in rats with a PCA alone by gavaging with blood and a higher incidence of more severe overt encephalopathy was induced in rats with a PCA combined with either cirrhosis or partial hepatectomy by gavaging with blood. Although these models of PSE were associated in some instances with plasma ammonia concentrations about 25 times higher than normal, no seizures were observed. CONCLUSION: A syndrome that resembles overt PSE in humans can be induced in the rat with a PCA by further reducing hepatocellular function and also gavaging with blood. Although the rat with a PCA has been. extensively used as a model in studies relating to the pathogenesis of PSE, a syndrome resembling overt PSE in humans cannot readily be induced in rats with a PCA.

Ammonia↗
PubMed1997

Local perfusion of diazepam attenuates interictal and ictal events in the bicuculline model of epilepsy in rats.

PURPOSE: We evaluated the efficacy of local perfusion of diazepam (DZP) in suppression of EEG spikes and behavioral seizures produced by bicuculline methiodide (BMI) applied to rat sensory motor cortex and hippocampus. METHODS: Data were obtained from 37 rats implanted with EEG head plugs and perfusion cannulas. BMI 4 mM, 5 microliters was infused on neocortex through the epidural space in 23 rats. BMI 0.1 mM, 2 microliters was infused into the left hippocampus in 14 rats. RESULTS: DZP 0.75-1.0 mg markedly reduced the spiking to a level of 9.9 +/- 15.8% of baseline for DZP as compared with 90.2 +/- 57.9% of baseline for vehicle-treated rats. DZP reduced spiking in a hippocampal BMI focus to 1.9 +/- 2.4% of baseline spiking, as compared with 98.0 +/- 95.6% of that in vehicle-treated animals. The amount of spread of solution was estimated with methylene blue (MB) injections. Ictal events also were attenuated. In most of the animals, systemic levels of DZP were unmeasurable and injection on the contralateral side did not reduce spiking. CONCLUSIONS: These findings suggest that focal application of antiepileptic drugs (AEDs) in brain may be a useful new avenue for therapy of intractable partial seizures.

Administration, Topical↗
PubMed1997

No mechanical role for vinculin in strain transduction in primary bovine osteoblasts.

Vinculin is thought to play a central role in linking the actin cytoskeleton to the integrin adhesion proteins of focal contacts and also in cell-cell adhesion sites. We have investigated aspects of attachment and the transduction of mechanical stimulation on the function of vinculin and its assembly in primary bovine osteoblasts. The dynamic attachment process was concomitant with the reassembly of vinculin from a soluble cytoplasmic pool into Triton-insoluble focal adhesions. Immunoblotting experiments demonstrated a slight increase in the amount of vinculin concentrated in focal contacts that was paralleled by a discrete decrease in the Triton-soluble fraction of cytoplasmic vinculin. Sixty cycles of 1 Hz deformations at 0.02% (hypophysiological, no change in cell division rate), 0.2% (within the normal physiological range), and 1% (hyperphysiological) resulted in a rapid and reversible disassembly of vinculin from focal contacts to a homogeneous cytoplasmic localization, although alterations in the shape and morphology of cells could not be detected. Although all mechanical loading protocols dramatically depleted vinculin from focal contacts, its initial distribution in adhesion plaques was fully restored within the next 60 min, demonstrating the highly dynamic and reversible shift of this protein from a membrane-associated pool to the cytoplasm. By first depleting vinculin from the focal adhesion sites by applying 0.02% strain, waiting 60 s, and then applying 0.2% strain, we show that the transduction of mechanical deformation was identical with controls that had not been pretreated. This indicates that vinculin does not play a role in mechanical transduction, that significant mechanical forces are not transmitted through vinculin, and also that loss of vinculin at the focal adhesion site does not have significant effects, in the short term, on cell adhesion.

Animals↗
PubMed1997

Complete ophthalmoplegia after zoster ophthalmicus.

Complete ophthalmoplegia following herpes zoster ophthalmicus (HZO) is rare. We report three cases of HZO-associated complete ophthalmoplegia and review thirteen additional cases reported in the English language medical literature over the past 30 years. HZO-associated complete ophthalmoplegia occurs mostly in individuals over the age of 50 years and usually occurs within one to two weeks of the development of cutaneous HZO. The prognosis for recovery is good, with-significant improvement typically seen within 2 months and complete or near resolution within 18 months time.

Aged↗