PubMed Health⌕ Search

Biomedical subjects

R A Komorowski

Publications and source records attributed to R A Komorowski.

At least 37 records · Page 2Linked to original sources
PubMed1995

Increased signal in the normal supraspinatus tendon on MR imaging: diagnostic pitfall caused by the magic-angle effect.

OBJECTIVE: Increased signal intensity within the distal portion of the supraspinatus tendon during MR imaging is a frequent observation even in healthy subjects. This finding has been variously attributed to the presence of fat, muscle, connective tissue, abnormal vascularity, or degenerative changes. More recently, the effect of tendon orientation in the static magnetic field (Bo) has been implicated. It has been shown that tendons at the magic angle of 55 degrees to Bo show markedly increased signal. This study was designed to determine the contribution of the magic-angle effect to the MR signal in the distal portion of the supraspinatus tendon. SUBJECTS AND METHODS: Five healthy volunteers were imaged in a 1.5-T unit using short TR/TE sequences in standard supine position; they were then reimaged laterally flexed at the waist to reorient the plane of the distal portion of the supraspinatus tendon by approximately 20 degrees relative to Bo. In the second part of the study, three cadaveric shoulders were similarly imaged, first in standard position and then reoriented approximately 35 degrees by simple rotation of the specimen. The supraspinatus tendon was evaluated in each subject by noting the length of the segment with increased signal and the position of this segment relative to the insertion of the tendon on the greater tuberosity. Comparisons were made for each live and cadaveric subject between neutral and rotated positions. RESULTS: Segments of increased signal changed in length and position for each live and cadaveric subject from the neutral to the reoriented position. CONCLUSION: Our study suggests that tendon orientation contributes significantly to the presence of increased signal within the supraspinatus tendon, as caused by the magic-angle effect. Failure to recognize this effect may lead to diagnostic inaccuracy when evaluating the rotator cuff on short TR/TE sequences.

Adult↗
PubMed1994

Focal masses in cirrhotic liver: CT and MR imaging features.

The development of hepatic cirrhosis triggers attempted repair through regenerative nodules of parenchyma among bands of scar tissue. Some authors believe that this regeneration initiates an evolutionary process that may lead to nodular enlargement and cellular dedifferentiation to malignancy. Both the destructive and reparative processes in cirrhosis produce changes that the radiologist must recognize when imaging the cirrhotic liver. This essay describes the CT and MR features of masses and masslike lesions in the cirrhotic liver, including the identifying characteristics and overlapping appearances of CT and MR.

Carcinoma, Hepatocellular↗
PubMed1994

Hydroxyethyl starch deferoxamine, a novel iron chelator, delays diabetes in BB rats.

Hydroxyl radicals (.OH) may contribute to beta cell death. Because iron catalyzes .OH production, we examined whether administration of a novel, long-acting iron chelator, hydroxyethyl starch-deferoxamine (HES-DFO) could prevent diabetes in spontaneously diabetic biobreeding (BB) rats. In our colony, a peripheral lymphocyte count (PBLC) < 4200 mm3 has an 88% positive predictive value for onset of diabetes mellitus (DM). Rats with PBLC < 4200 mm3 were randomized at 6 weeks of age to receive 50 mg/kg of HES-DFO (a high molecular weight hydroxyethyl starch-conjugated derivative of deferoxamine) or equimolar hydroxyethyl starch (HES) alone given intraperitoneally three times weekly until DM or 120 days of age. Administration of HES significantly decreased the incidence of IDDM to 57% as compared with the incidence of 87% in the lymphopenic unmanipulated BB rats in the colony (p < 0.01). Administration of HES-DFO further significantly decreased the incidence of IDDM to 31% as compared with the lymphopenic unmanipulated rats (p < 0.01). When analyzed by sex, 3 of 17 (18%) HES-DFO-treated males developed DM, versus 10 of 17 (58%) of HES-treated males (p < 0.05, chi square); 8 of 19 (42%) of HES-DFO-treated females developed DM, versus 11 of 20 (55%) HES-treated females (p = NS). There were no differences between the groups in (1) mean time of onset of DM, (2) serum iron levels at study entry and completion, (3) weekly hematocrits, (4) total lymphocyte counts; and (5) weekly weight gains.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Wound healing of KTP and argon laser lesions in the canine nasal cavity.

The potassium titanyl phosphate (KTP) and argon lasers are increasingly used in nasal and sinus surgery. Histologic effects of these lasers on living nasal tissue have not been investigated. Sixteen dogs underwent laser nasal surgery (eight for each laser). Flexible fiberoptic quartz fibers were used with both lasers to deliver the laser energy to the tissue. The dogs were allowed to heal and then underwent biopsy at 3, 7, 21, and 90 days postoperatively. The argon and KTP lasers had similar tissue effects. Histologically, a thin rim of coagulation necrosis and acute inflammation were seen at 3 days postoperatively. By 7 days, fibroblasts and granulation tissue were observed. At 21 days, fibroblast proliferation and re-epithelialization with respiratory epithelium were the predominant findings. Finally, at 90 days postoperatively, respiratory epithelium and submucosal structures were found overlying a plug of scar filling the defect in the septal cartilage. This healing was consistent through a wide range of energy densities. These lasers are easily used with sinus endoscopes and the operating microscope to allow access to difficult areas. These factors and the wound-healing characteristics noted in this study would seem to make them suited for use in rhinologic surgery.

Animals↗
PubMed1992

Short-term effect of silicone gel on peripheral nerves: a histologic study.

The effect of silicone gel on the peripheral nerve was studied in Sprague-Dawley rats. Silicone gel was placed either extraneurally (N = 36) adjacent to or injected directly in the sciatic nerve (N = 20). Nerve histology was studied every 2 weeks over a 20-week period. Extraneural silicone gel elicited an intense inflammatory response characterized initially by predominantly histiocytes with a few eosinophils, lymphocytes, and foreign-body giant cells. The cellular response peaked at 4 weeks, after which time collagen deposition increased and the thickness of the cellular infiltrate surrounding the gel decreased. The gel was temporarily contained by the inflammatory response, but throughout the time course of the study, gel migration and breakup into smaller droplets occurred. Each droplet appeared to initiate the inflammation-fibrosis cycle anew. Perineural fibrosis was marked by 20 weeks, but there was no penetration of the epineurium by the gel. Intraneurally injected silicone gel also caused a delayed, but similar inflammatory response, eventually followed by fibrosis surrounding the gel. Intraneural gel tended to remain in larger droplets and did not migrate over the duration of this study. No direct evidence of gel toxicity to peripheral nerves was observed in either the extraneural or intraneural gel groups despite the initial intense inflammatory response and subsequent fibrosis.

Animals↗
PubMed1991

Ampullary tumor caused by metastatic renal cell carcinoma.

In this paper we report the case of a renal cell carcinoma (RCC) metastatic to the ampullary region. The patient presented with severe anemia due to blood loss from the ampullary tumor 11 years after nephrectomy for the primary renal cancer. The diagnosis was established by means of endoscopy and biopsy.

Ampulla of Vater↗
PubMed1991

Ampullary hamartoma: endoscopic diagnosis and treatment.

This study shows a patient who presented with intermittent biliary tract obstruction caused by ampullary hamartoma. Endoscopic retrograde cholangiopancreatography showed a large ulcerated papilla and dilated biliary ducts. Tissue diagnosis was established by a large particle biopsy obtained with a snare. The patient underwent a successful endoscopic sphincterotomy and has remained symptom free for 4 years.

Aged↗
PubMed1991

Hyperplastic gastropathy. Clinicopathologic correlation.

Assessment of gastric histology in patients with hyperplastic gastritis is now possible using new endoscopic biopsy techniques that obtain a full-thickness gastric mucosal biopsy. Thirty-one patients with hyperplastic gastropathy and full-thickness gastric mucosal biopsies or gastric resections were seen during a 13-year period. Six patients had Zollinger-Ellison syndrome (ZE) with gastric gland hyperplasia; six had Menetrier's disease with foveolar hyperplasia and gland atrophy; and a single patient with hyperplastic hypersecretory gastropathy (HHG) was seen. The majority of patients, 18 of 31 with large folds, had peptic disease. The enlarged gastric folds were due to edema and inflammation. Discordant clinical findings and gastric pathology were seen in four patients: three of the 18 patients with peptic disease had histology typical of ZE (two patients) or Menetrier's disease. None of the three patients have developed a syndrome on follow-up ranging up to 5 years. Also, the patient with HHG had the gastric histology seen in Menetrier's disease. One patient with Menetrier's disease had areas of atrophic gastritis interspersed between the hyperplastic gastritis. In summary, the majority of patients with endoscopic hyperplastic gastropathy had gastritis on histologic examination. Most patients with a clinical syndrome associated with hyperplastic gastritis showed histology typical for the syndrome; however, clinical-histologic concordance was not absolute. In a small minority of cases, a patient with one clinical syndrome had the histology typical of another.

Adult↗
PubMed1991

Assessment of ampulla of Vater pathology. An endoscopic approach.

One hundred eighty-nine endoscopic biopsies of the papilla of Vater were obtained from 125 patients during a 10-year period. Chronic inflammation was the most common histologic change identified. Of the 44 patients with papillary neoplasia, 42 were diagnosed by endoscopic biopsy. Sixteen of the 18 patients with invasive carcinoma were diagnosed by biopsy. Follow-up biopsies in patients endoscopically managed demonstrated recurrent tumors in 6 of 11 patients. With advances in instrumentation and techniques, pathologists can expect to see increasing numbers of ampullary biopsies. When multiple biopsy fragments are obtained and step sectioned, the diagnostic reliability of endoscopic biopsies in patients with tumors and carcinoma is greater than 90%. The morphologic spectrum of papillary lesions is similar to that seen in the colon with some significant exceptions. Tumor morphology varied considerably from area to area. Variations were seen in the basic architecture (villous-tubular), grade of dysplasia, presence of malignancy, and invasion from fragment to fragment, and in some cases from microscopic field to field. Another notable difference between the ampulla and colon is the rich mucosal lymphatic network of the ampullary region. Thus, any carcinoma invading the lamina propria was diagnosed as invasive carcinoma.

Adenoma↗
PubMed1990

Quantitative ultrasonic assessment of normal and ischaemic myocardium with an acoustic microscope: relationship to integrated backscatter.

PURPOSE OF INVESTIGATION: The aim was to study ultrasonic propagation properties of normal and ischaemic myocardium with a scanning laser acoustic microscope and to correlate these changes with ultrasonic backscatter. DESIGN: Myocardial ischaemia was produced by total occlusion of left anterior descending coronary artery in anaesthetised open chest dogs. Myocardium supplied by left circumflex coronary artery served as normal control. IBR5, an optimum weighted frequency average (4-6.8 MHz) of the squared envelope of diffraction corrected backscatter, was measured in vivo. Ultrasonic attenuation coefficient, an index of loss per unit distance, the propagation speed and heterogeneity index were measured from normal and ischaemic regions with a scanning laser acoustic microscope which operates at 100MHz in vitro. Myocardial water content of normal and ischaemic myocardium was also estimated. SUBJECTS: Were five anaesthetised mongrel dogs. RESULTS: Attenuation coefficient of 33.8(SD4.2) dB.mm-1 in the ischaemic tissue was lower than 63.8(17.2) dB.mm-1 in the normal tissue (p less than 0.01). Ultrasonic speed was lower in ischaemic than normal myocardium at 1584(25) v 1612(35) m.s-1 (p less than 0.05). Heterogeneity index of 11(7) m.s-1 in the ischaemic region was lower than 14(8) m.s-1 in the normal region (27% reduction, p less than 0.05). IBR5 and myocardial water content were higher in the ischaemic than the normal myocardium: -37.2(SEM1.8) dB v -46.6(0.6) dB, (p less than 0.01) and 80.9(0.0)% v 78(0.2)%, (p less than 0.05) respectively. CONCLUSION: Ultrasonic properties of the myocardium are significantly altered during acute ischaemia.

Animals↗
PubMed1990

Histologic spectrum of diversion colitis.

Biopsy specimens taken from six patients with diversion colitis, an inflammatory process that occurs in the bypassed colonic segment after diversion of the fecal stream, showed a spectrum of histologic changes ranging from mild colitis to those seen in severe active chronic ulcerative colitis. Histologic abnormalities included aphthous ulcers, crypt distortion, atrophy and abscesses, a villous colonic surface, and a mixed acute and chronic inflammatory infiltrate with patchy lymphoid hyperplasia. Accurate pathologic diagnosis is dependent on clinical history, comparison of histologic morphology in both colonic segments, and response to therapy with local application of short chain fatty acids.

Adult↗
PubMed1989

Treatment of diversion colitis with short-chain-fatty acid irrigation.

A condition known as diversion colitis frequently develops in segments of the colorectum after surgical diversion of the fecal stream; it persists indefinitely unless the excluded segment is reanastomosed. The disease is characterized by bleeding from inflamed colonic mucosa that mimics the bleeding of idiopathic inflammatory bowel disease, and it may culminate in stricture formation. We hypothesized that this condition is caused by the absence of luminal short-chain fatty acids, the preferred metabolic substrates of colonic epithelium. We studied four patients with diversion colitis, none of whom had evidence of Crohn's, idiopathic ulcerative, or infectious colitis. The excluded segment of the rectosigmoid contained negligible concentrations of short-chain fatty acids. When D-glucose was instilled, it did not undergo appreciable anaerobic fermentation. Instillation of a solution containing short-chain fatty acids twice daily resulted in the disappearance of symptoms and the inflammatory changes observed at endoscopy, over a period of four to six weeks. Remission has been maintained for up to 14 months (in one patient) by instillation daily to twice weekly. Administering enemas containing isotonic saline, or omitting treatment for periods of two to four weeks during the regimen, by contrast, did not produce any improvement or rapid relapse of the colitis. Histologic observation revealed a distinctive type of mucosal inflammation that resolved more slowly and less completely than the gross appearance of the inflamed mucosa. From these preliminary studies we infer that diversion colitis may represent an inflammatory state resulting from a nutritional deficiency in the lumen of the colonic epithelium, which is effectively treated by local application of short-chain fatty acids, the missing nutrients.

Colitis↗
PubMed1989

Porokeratosis of mibelli in transplant recipients.

Four of 602 renal and hepatic transplant recipients had porokeratosis of Mibelli develop in the posttransplant period. Porokeratosis is an uncommon, autosomally dominant inherited disorder that presents in adolescence as a proliferation of an abnormal clone of epidermal cells. Clinically, it is characterized by nonhealing plaques that develop most commonly on the limbs. Porokeratosis, a premalignant condition, must be added to the list of potential cutaneous complications seen in immunosuppressed organ transplant recipients.

Adult↗
PubMed1988

Suloctidil-induced hepatotoxicity.

Suloctidil is a new drug that is currently being evaluated in many clinical trials for use in dementia and thrombotic disorders. Hepatotoxicity has to date been reported exclusively in the European literature, and the few available histologic descriptions have been reported in the French language. We report a case of suloctidil-induced hepatotoxicity documented by serum liver biochemical tests and liver biopsy. Histologic features included focal necrosis of hepatocytes, mild hyperplasia of Kupffer cells, and other features suggestive of mild acute hepatitis.

Aged↗
PubMed1988

Occult thyroid pathology in the young adult: an autopsy study of 138 patients without clinical thyroid disease.

Thyroid glands from autopsies on 138 adults, ages 20 to 40 years, with no known clinical or laboratory evidence of thyroid disease, were serially sectioned at 2 mm intervals and microscopically examined for occult thyroid disease and anatomic variations. Occult papillary carcinoma was found in 3% of the glands, along with a single case of medullary carcinoma. The prevalence of occult thyroid carcinoma in this group of young adults is significantly less than that reported in the literature in people over forty (P less than .001). The glands demonstrated a number of other morphologic changes of importance to surgical pathologists. The thyroid capsule was incomplete in 62% of the glands. Thyroid follicles were found in the capsule in 14% of cases and thyroid follicles or nodules were outside the gland in perithyroid connective tissue in 88% of cases. Thyroid follicles were identified in 7% of cases in perithyroid strap muscles attached to the pyramidal lobe. A number of other, less common anatomic variations were also seen.

Adenoma↗
PubMed1988

Occult carcinoma of the breast masquerading as primary adenocarcinoma of the small intestine. A case report.

A fifty-year-old woman with abdominal pain, diarrhea, and weight loss ultimately required exploratory laparotomy. The entire small intestine was extensively infiltrated by poorly differentiated adenocarcinoma; mesenteric lymph nodes and surrounding omentum were involved, but no extragastrointestinal tumor was found. A presumptive diagnosis of unresectable primary carcinoma of the small bowel was made. Chemotherapy was initiated with 5-fluorouracil 300 mg/m2/day by continuous intravenous infusion. Nine months later a left breast mass with multiple ipsilateral axillary and supraclavicular lymph nodes developed; biopsy revealed a poorly differentiated adenocarcinoma morphologically identical to the tumor involving her small bowel. In spite of breast irradiation and systemic hormonal therapy, the patient deteriorated rapidly and died from progressive metastatic disease.

Breast Neoplasms↗
PubMed1988

Control mechanisms of sphincter of Oddi contraction rate in the opossum.

Our aim in this study is to determine whether extrinsic autonomic nerves regulated spike-burst rate in the opossum sphincter of Oddi (SO) during fasting or after feeding. We implanted electrodes on the distal SO, proximal SO, gastric antrum, duodenum, and jejunum of 20 animals. A cut transection and reanastomosis was done at different levels of the SO to interrupt putative extrinsic or intrinsic nerves, or the SO was painted with phenol to impair extrinsic nerves. Like controls, animals with a cut and reanastomosis at the proximal SO or at the SO-duodenal junction showed a normal fasting pattern of cyclic changes in SO spike-burst rate. In contrast, animals treated by a distal SO cut or phenol treatment at the distal SO lost the normal cyclic pattern of SO spike bursts and had a constant rate of approximately 4/min. A cut through the middle SO uncoupled the spike bursts in the proximal and distal SO. After feeding, all animals developed an SO spike-burst rate of 5-6/min that lasted for several hours. We conclude that the normal fasting pattern of SO spike bursts is regulated by extrinsic nerves that ascend cephalad along the sphincter segment, whereas the sustained increase in SO spike-burst rate after feeding is at least in part hormonal.

Action Potentials↗