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Biomedical subjects

J Berg

Publications and source records attributed to J Berg.

At least 91 records · Page 5Linked to original sources

Prognosis after surgical excision of cerebral meningiomas in cats: 17 cases (1986-1992).

Long-term follow-up information was obtained for 17 cats with cerebral meningiomas treated by surgical excision. Three cats died or were euthanatized in the immediate postoperative period: 2 cats, because of brain herniation and 1 cat, because of acute renal failure. In the remaining 14 cats, most clinical signs resolved within 1 week of surgery. Three cats (21.4%) had confirmed or presumed local tumor recurrence. Two of these cats developed recurrent neurologic signs, and died or were euthanatized at 3 and 9 months, respectively, after surgery. One cat was euthanatized for an unrelated problem 72 months after surgery, and on postmortem examination, had a recurrent meningioma at the surgery site. The remaining 11 cats (78.6%) did not develop evidence of local tumor recurrence within follow-up periods ranging from 18 to 47 months (median, 27 months).

Animals↗

Effect of protamine sulfate on the permeability properties of the mammalian urinary bladder.

Protamine sulfate (PS, an arginine-rich protein of molecular weight 5,000) has been reported to affect the ionic permeability of gallbladder epithelium, the permeability of cultured epithelial cells to mannitol, and the permeability of endothelial cell layers to albumin. Although the effect of PS has been widely investigated, the mechanism of its action on membrane permeability is presently unknown. The effect of PS on the rabbit urinary bladder epithelium was studied using both transepithelial and intracellular microelectrode techniques in conjunction with equivalent circuit analysis. The addition of 100 micrograms/ml of PS to a NaCl-containing mucosal solution caused (over a 40-min period) a large increase in the transepithelial conductance (Gt) and a transient hyperpolarization of the transepithelial voltage (Vt) followed by a depolarization of Vt. This secondary depolarization of Vt was not present if the mucosal solution was a KCl or a K-gluconate Ringer. The PS-induced increase in Gt was due to an increase in the apical membrane permeability to both cations (Na+ or K+) and anions (Cl- or gluconate). Further studies revealed the following features of the PS-induced conductance. (i) Trypsin inhibits the PS effect; however, this was due to PS hydrolysis by trypsin and not a membrane effect. (ii) Mucosal PS partially inhibited the PS-induced apical membrane conductance. (iii) The ability of PS to increase the membrane conductance was enhanced when the apical membrane potential was cell interior negative. (iv) The rate of conductance change (at any given membrane potential) was a saturating function of the PS concentration. This finding suggests that PS must interact with a membrane binding site before it can induce a change in the membrane conductance. (v) Lanthanum inhibited the PS-dependent conductance by two different mechanisms. One was as a reversible blocker of the PS-induced conductance. The other was by inhibiting the interaction between PS and a membrane binding site. A kinetic model is developed to describe the steps involved in the increase in membrane conductance.

Animals↗

Treatment by digital amputation of subungual squamous cell carcinoma in dogs: 21 cases (1987-1988)

Malignant digital tumors were diagnosed in 62 dogs during a 1-year period. Twenty-one (33.9%) of the dogs had subungual squamous cell carcinoma. Each of these dogs had involvement of single digits. Sixteen (76.2%) of the dogs with squamous cell carcinoma were large-breed dogs, and 15 (71.4%) had predominantly black coats. Labrador Retrievers (n = 5, 23.8%) and Standard Poodles (n = 3, 14.3%) were the most commonly represented purebreeds. None of the dogs had evidence of metastases prior to treatment. All 21 tumors were treated by amputation of the involved digit. Histologic evidence of neoplastic bone invasion was found in 15 of the 21 amputated digits (71.4%). Local tumor recurrences were not observed. Only 1 dog developed documented metastatic disease; this dog was euthanatized because of pulmonary metastases 5 months after surgery. At the time of this report, 9 dogs (42.9%) were alive with no evidence of disease (median, 26 months after surgery), and 11 dogs (52.4%) had died or were euthanatized (median, 20 months after surgery). The cause of death in 7 dogs was known to be unrelated to squamous cell carcinoma, and the cause of death in 4 dogs was unknown. The 1-year and 2-year survival rates were 76.2% and 42.9%, respectively.

Amputation, Surgical↗

Treatment of dogs with osteosarcoma by administration of cisplatin after amputation or limb-sparing surgery: 22 cases (1987-1990).

Twenty-two dogs with appendicular osteosarcoma were treated by amputation (n = 17) or limb-sparing surgery (n = 5). All dogs were given cisplatin (60 mg/m2 of body surface, IV) at 3-week intervals, beginning 1 week after surgery. Number of cisplatin treatments ranged from 1 to 6. Survival data for the 22 dogs were compared with survival data from a historical control group consisting of 162 dogs with appendicular osteosarcoma treated by amputation alone. Median survival time for the 22 dogs given cisplatin was estimated to be 46.4 weeks, and 1- and 2-year survival rates were estimated to be 45.5 and 20.9%, respectively. Survival time was significantly (P less than 0.0001) longer for treated dogs than for control dogs. Statistically significant relation was not found between survival time and number of cisplatin treatments. Three dogs were alive with no evidence of disease at the time of reporting. Of the remaining 19 dogs, 14 (73.4%) were euthanatized for problems documented to be related to metastases. Nine (47.4%) dogs were euthanatized because of bone metastases, and 5 (26.3%) were euthanatized because of pulmonary metastases. The proportion of dogs euthanatized because of bone metastases was significantly (P less than 0.0001) higher for treated than for control dogs. Median survival times for dogs developing bone and lung metastases were estimated to be 51.2 weeks and 21.2 weeks, respectively; however, this difference was not statistically significant. One local tumor recurrence was observed among dogs that had limb-sparing surgery. Significant difference in survival time was not observed between dogs that had limb-sparing surgery and dogs that underwent amputation.

Amputation, Surgical↗

Prognosis for dogs with appendicular osteosarcoma treated by amputation alone: 162 cases (1978-1988).

Long-term follow-up information pertaining to 162 dogs with appendicular osteosarcoma treated by amputation alone was collected from 17 veterinary institutions. The majority (72.5%) of dogs died or were euthanatized because of problems documented to be related to metastases. The first clinically apparent sites of metastasis were the lungs (60.8% of total), the skeleton (5.2%), or both (4.6%). A Kaplan-Meier survivorship distribution was plotted on the basis of available survival time data in all 162 dogs. The mean and median survival times were estimated to be 19.8 and 19.2 weeks, respectively, and the 1- and 2-year survival rates were estimated to be 11.5 and 2.0% respectively. Statistically significant relationships were not found between survival time and reporting institution, gender, site of primary tumor, whether the primary tumor was proximally or distally located, whether the primary tumor was located in the forelimb or hind limb, whether presurgical biopsy was performed, and whether death was tumor related. A significant (P less than 0.01) quadratic relationship was found between age and survival time. Survival time was longest in dogs 7 to 10 years old and was shorter in older and younger dogs.

Amputation, Surgical↗

Spinal lymphoma in cats: 21 cases (1976-1989).

Medical records of 21 cats with spinal lymphoma were reviewed. All cats were evaluated for neurologic deficits, although 85% of cats necropsied had multicentric disease. Eighty-one percent of cats had hind limb paresis. Results of FeLV tests were positive in 84.2% (16/19) of the cats, and 68.7% (11/16) of the cats had leukemic bone marrow. Spinal lymphoma was confirmed by necropsy in 13 cats, by examination of a biopsy specimen in 1 cat, and by examination of cells aspirated from an epidural lesion in 2 cats. In the remaining 5 cats, a presumptive diagnosis was made on the basis of neurologic examination findings, positive FeLV test results, and leukemic bone marrow. Nine cats were treated with chemotherapy alone. The complete remission rate was 50% in 6 cats given cyclophosphamide, vincristine, and prednisone. The median duration of complete remission was 14 weeks. Complete remissions were not observed in 3 cats given only corticosteroids. A single cat treated by laminectomy and postoperative chemotherapy had a prolonged remission (62 weeks). At necropsy, lymphoma of the CNS was limited to the vertebral canal in 10 of 13 cats; 2 cats had malignant tissue in the brain and vertebral canal, and in the remaining cat, the tumor extended into the brachial plexus. Most tumors extended over multiple vertebral bodies, and 4 cats had more than 1 level of spinal cord involvement. The lymphoma was high-grade lymphoblastic or immunoblastic type in all cats.

Animals↗

Modifying the request behaviour of clinicians.

AIM: To evaluate whether the feedback of laboratory use and cost data to clinicians modifies their request behaviour. METHODS: Over two years the effect of monthly feedback of clinical chemistry test use and revenue expenditure to three consultant physicians on their clinical chemistry and haematology requesting patterns was evaluated. Two physicians who received no information served as controls. RESULTS: Feedback over one year led to an immediate and sustained decrease of 15%, 27%, and 21% in clinical chemistry requests (p less than 0.01), tests (p less than 0.001), and revenue expenditure (p less than 0.001), respectively, and a 10% reduction in haematology tests (p less than 0.05) per outpatient visit. These changes persisted in the six months after the feedback was stopped. CONCLUSIONS: These results suggest that feedback of laboratory data to clinicians modifies their request behaviour and that supplying clinicians with information on what they do can influence the way they make decisions.

Clinical Laboratory Techniques↗

Coronary risk factors in middle-aged men as related to smoking, coffee intake and physical activity.

The relationship between lifestyle and coronary risk factors in blood was investigated in 165 middle-aged men. Plasma fibrinogen, serum triacylglycerols (TG), and apolipoprotein B (apo B) were higher, and high density lipoprotein cholesterol (HDLc) lower in smokers (n = 69) than in non-smokers (n = 96). By linear regression analysis there was a significant positive association between degree of smoking and either total cholesterol (TC), apo B, or plasma fibrinogen, whereas smoking was inversely related to HDLc. Smoking and coffee intake were positively correlated with an atherogenic index, reflecting the balance between low and high density lipoproteins. Sedentary men (n = 59) had higher mean TC, apo B, and atherogenic index than physically active men (n = 104). Smokers used salt more often than non-smokers. Physically active men used vegetables more often than sedentary men. Combining several habits into a "bad habit" score gave a high level of significance for its association with TC, apo B, and the atherogenic index. The results indicate that lifestyle may influence several blood factors involved in atherosclerosis development.

Adult↗

Bispecific antibodies that mediate killing of cells infected with human immunodeficiency virus of any strain.

Although AIDS patients lose human immunodeficiency virus (HIV)-specific cytotoxic T cells, their remaining CD8-positive T lymphocytes maintain cytotoxic function. To exploit this fact we have constructed bispecific antibodies that direct cytotoxic T lymphocytes of any specificity to cells that express gp120 of HIV. These bispecific antibodies comprise one heavy/light chain pair from an antibody to CD3, linked to a heavy chain whose variable region has been replaced with sequences from CD4 plus a second light chain. CD3 is part of the antigen receptor on T cells and is responsible for signal transduction. In the presence of these bispecific antibodies, T cells of irrelevant specificity effectively lyse HIV-infected cells in vitro.

Acquired Immunodeficiency Syndrome↗

Treatment of posttraumatic carinal stenosis by balloon dilation during thoracotomy in a cat.

A cat with posttraumatic stenosis of the terminal part of the thoracic portion of the trachea and carina was successfully treated by balloon dilation of the stenosis during thoracotomy. Thoracotomy was performed at the right fifth intercostal space, and the stenosis was dilated, using a balloon-tipped catheter passed through an endotracheal tube. A 6-week course of orally administered corticosteroids was instituted after surgery. Balloon dilation during thoracotomy is a technically simple procedure for treatment of stenosis of the thoracic portion of the trachea.

Animals↗

Feedback of laboratory usage and cost data to clinicians: does it alter requesting behaviour?

In a 1 year prospective study we evaluated the effect of feedback of laboratory data on the requesting behaviour of physicians in general medicine. Data on within-hours and out-of-hours clinical chemistry laboratory usage and revenue expenditure for inpatients and outpatients, expressed in terms of clinical workload, were supplied monthly to a group of three consultant physicians in general medicine. With these data the physician could monitor his performance over a period of time and compare it with that of his peers. Two consultants in general medicine who received no information served as controls. Over a period of 6 months, there was a 25%, 13% and 18% decrease in tests (P less than 0.01), requests (P less than 0.05) and revenue expenditure (P less than 0.01) per outpatient visit, respectively, in the intervention group of physicians following the introduction of feedback when compared to their baseline period and to the control group. The decrease (P less than 0.01) was in the commonly requested and 'seemingly cheap' tests. There was no significant change in laboratory use and expenditure on inpatients. The feedback of laboratory data was acceptable to the physicians, raised their awareness of laboratory usage and costs and decreased laboratory workload and expenditure.

Feedback↗

In vitro assay of nuclear uptake of doxorubicin hydrochloride in osteosarcoma cells of dogs.

A rapid, simple chemosensitivity assay, assessing tumor cell nuclear uptake of doxorubicin hydrochloride, was evaluated in 16 dogs with appendicular osteosarcoma. Doxorubicin was administered to dogs in 5 biweekly treatments, and surgical resection was performed after the second or third treatment. The chemosensitivity assay was performed on biopsy specimens from all dogs before chemotherapy. It was repeated on tissue from resected tumors, and tumors were evaluated histologically to determine the degree of necrosis resulting from chemotherapy. Disease-free and total survival time correlated significantly (P less than 0.05 in both cases) with the degree of postchemotherapy necrosis of the primary tumors. Significant correlation was not apparent between the percentage of tumor cells with nuclear uptake of doxorubicin (in either biopsy or resection samples) and disease-free or total survival time. The percentage of cells with nuclear uptake of doxorubicin in surgically resected tumors correlated significantly (P less than 0.05) with percentage of necrosis.

Animals↗

Giant cell tumor of the accessory carpal bone in a dog.

A 4-year-old Springer Spaniel was referred because of a 6-week history of progressive left forelimb lameness. A marked pain response was elicited by palpation over the left accessory carpal bone. Radiography revealed a lytic, markedly expansile lesion of the accessory carpal bone. The bone was excised, and pancarpal arthrodesis was performed. Histologic examination of the excised bone revealed giant cell tumor. At 14 months after surgery, the dog was using the limb normally. Radiography of the carpus revealed satisfactory progression of the arthrodesis, and thoracic radiographs were negative for metastases.

Animals↗

Studies of the cellulolytic system of the filamentous fungus Trichoderma reesei QM 9414. Substrate specificity and transfer activity of endoglucanase I.

Endoglucanase I from the filamentous fungus Trichoderma reesei catalyses hydrolysis and glycosyl-transfer reactions of cello-oligosaccharides. Initial bond-cleaving frequencies determined with 1-3H-labelled cello-oligosaccharides proved to be substrate-concentration-dependent. Using chromophoric glycosides and analysing the reaction products by h.p.l.c., kinetic data are obtained and, as typical for an endo-type depolymerase, apparent hydrolytic parameters (kcat., kcat./Km) increase steadily as a function of the number of glucose residues. At high substrate concentrations, and for both free cellodextrins and their aromatic glycosides, complex patterns (transfer reactions) are, however, evident. In contrast with the corresponding lactosides and 1-thiocellobiosides, and in conflict with the expected specificity, aromatic 1-O-beta-cellobiosides are apparently hydrolysed at both scissile bonds, yielding the glucoside as one of the main reaction products. Its formation rate is clearly non-hyperbolically related to the substrate concentration and, since the rate of D-glucose formation is substantially lower, strong indications for dismutation reactions (self-transfer) are again obtained. Evidence for transfer reactions catalysed by endoglucanase I further results from experiments using different acceptor and donor substrates. A main transfer product accumulating in a digest containing a chromophoric 1-thioxyloside was isolated and its structure elucidated by proton n.m.r. spectrometry (500 MHz). The beta 1-4 configuration of the newly formed bond was proved.

Cellulase↗