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Biomedical subjects

J Welch

Publications and source records attributed to J Welch.

At least 91 records · Page 5Linked to original sources
PubMed1990

The use of fibrin glue in intracranial procedures: preliminary results.

Intracranial procedures always have the potential of cerebrospinal fluid (CSF) leakage postoperatively. Sealing all routes of CSF drainage to the outside of the intracranial contents is essential. This is usually achieved with muscle and fat plugs, homograft dura, fascia, and suture. The use of a fibrin glue might affect and lessen the likelihood of a CSF leak. Eight clinical cases of various intracranial procedures using a simple, two-part patient autologous cryoprecipitate fibrinogen and bovine thrombin glue are described. Preliminary results of up to 1 year show no CSF leakage nor adverse reactions to the fibrin glue. The production method and material characteristics are briefly compared with other currently described autologous fibrin glue formulations. This version is similar in strength to other formulations, yet is simpler and more convenient to produce. The use of this autologous fibrin glue appears to provide an adjunct to commonly employed packing techniques in a convenient and effective manner. With more experience, fibrin glue might become an even more important tool in intracranial procedures.

Adult↗
PubMed1989

Structure of droperidol-ethanol (1/1).

1-(1-[4-(4-Fluorophenyl)-4-oxobutyl]-1,2,-3,6-tetrahydro-4-pyridyl)-1,3- dihydro-2H-benzimidazol-2-one ethanol solvate, C22H22FN3O2.C2H6O, Mr = 426.3, triclinic, P1, a = 6.083 (3), b = 10.296 (1), c = 16.018 (2) A, alpha = 100.93 (1), beta = 92.72 (2), gamma = 96.27 (2) degrees, V = 976.7 A3, Z = 2, Dx = 1.45 g cm-3, Mo K alpha, lambda = 0.71073 A, mu = 0.97 cm-1, F(000) = 452, T = 90 (2) K, final R = 0.046 for 2261 observed reflections. The title compound crystallizes with the droperidol skeleton extended and a solvated ethanol molecule disordered about an inversion center. The ethanol molecule forms a hydrogen bond to the droperidol skeleton at ketone atom O(1) on the imidazole ring.

Chemical Phenomena↗
PubMed1989

Hepatitis B infections after gynaecological surgery.

When acute hepatitis B developed in 3 patients who had had gynaecological surgery, the surgeon was found to be a carrier of hepatitis B e antigen. Of 268 patients operated on by this surgeon in one hospital, 247 were screened for markers of recent or current hepatitis B. 22 (9%) had such markers, associated with symptoms in 5. The operations carrying greatest risk of infection were hysterectomy (10/42) and caesarean section (10/51). These findings strengthen the case for vaccination of all surgeons and medical students against hepatitis B.

Acute Disease↗
PubMed1989

The CUP2 gene product regulates the expression of the CUP1 gene, coding for yeast metallothionein.

The yeast CUP1 gene codes for a copper-binding protein similar to metallothionein. Copper sensitive cup1s strains contain a single copy of the CUP1 locus. Resistant strains (CUP1r) carry 12 or more multiple tandem copies. We isolated 12 ethyl methane sulfonate-induced copper sensitive mutants in a wild-type CUP1r parental strain, X2180-1A. Most mutants reduce the copper resistance phenotype only slightly. However, the mutant cup2 lowers resistance by nearly two orders of magnitude. We cloned CUP2 by molecular complementation. The smallest subcloned fragment conferring function was approximately 2.1 kb. We show that CUP2, which is on chromosome VII, codes for or controls the synthesis or activity of a protein which binds the upstream control region of the CUP1 gene on chromosome VIII. Mutant cup2 cells produced extremely low levels of CUP1-specific mRNA, with or without added copper ions and lacked a factor which binds to the CUP1 promoter. Integrated at the cup2 site, the CUP2 plasmid restored the basal level and inducibility of CUP1 expression and led to reappearance of the CUP1-promoter binding factor. Taken collectively, our data establish CUP2 as a regulatory gene for expression of the CUP1 metallothionein gene product.

Carrier Proteins↗
PubMed1989

Effect of colostrum intake on plasma glucose, non-esterified fatty acid and glucoregulatory hormone patterns in the neonatal pig.

The effect of colostrum on endocrine and metabolic factors affecting glucose homeostasis was evaluated in 60 neonatal pigs that were fasted, fed (nursed ad libitum) or limit-fed colostrum (25% ad libitum, 4-hr interval feeding). Plasma acquired at birth (t0), and after 10, 20 and 30 hr (t10, t20 and t30, respectively) was analyzed for glucose, non-esterified fatty acids (NEFA), and the glucoregulatory hormones--insulin, glucagon, cortisol, growth hormone and catecholamines. The concentration of glucose and NEFA was similar among treatment groups at birth and increased in proportion to the quantity of colostrum consumed. Pigs fed ad libitum achieved and maintained a higher (greater than or equal to 40%; P less than .01) glucose concentration when compared to fasted neonates. Limit-fed counterparts also achieved and maintained higher levels, with glucose concentration being approximately 20% higher throughout (P less than .05). Fed pigs maintained NEFA concentrations which were approximately 2.5-fold to 4-fold greater than that of fasted pigs (P less than .05). Likewise, limit-fed pigs tended (P = .19) to have elevated NEFA concentrations and a lower (P less than .05) insulin:glucagon molar ratio. An inverse relationship was observed between colostrum intake and plasma concentrations of cortisol and growth hormone. Concentrations of epinephrine and norepinephrine tended (P greater than .10) to be elevated in fed pigs, relative to those of fasted counterparts. Provision of even limited quantities of colostrum is therefore beneficial to the glucoregulatory response in newborn pigs.

Aging↗
PubMed1989

The CUP2 gene product, regulator of yeast metallothionein expression, is a copper-activated DNA-binding protein.

CUP2 is a regulatory gene controlling expression of CUP1, which encodes the Cu-binding yeast metallothionein. CUP2, which is identical to the ACE1 gene, encodes a Cu-regulated DNA-binding protein. The CUP2 protein contains a cysteine-rich DNA-binding domain dependent on Cu+ and Ag+ ions which bind the cysteine residues and direct the refolding of the metal-free apoprotein. CUP2 mutant alleles from Cu-sensitive yeast strains have point mutations affecting the DNA-binding activity. These results establish CUP2 as the primary sensor of intracellular Cu+ in the yeast Saccharomyces cerevisiae, functioning as a Cu+-regulated transcriptional activator.

Amino Acid Sequence↗
PubMed1988

Asymmetries in ON and OFF visual pathways of humans revealed using contrast-evoked cortical potentials.

Positive- and negative-contrast stimuli yield the perceptions of brightness and darkness, respectively, and are processed separately by ON and OFF neural pathways. The properties of these morphologically and pharmacologically distinct subsystems were measured in humans by recording visual evoked potentials (VEPs). These electrical responses from the visual cortex were elicited by novel positive- and negative-contrast stimuli, designed to emphasize, selectively, contributions from ON and OFF pathways. Results revealed differential processing of the two types of contrast information, suggesting asymmetries in ON and OFF subsystems; OFF subsystems have finer spatial tuning and greater contrast gain than ON subsystems. These VEPs may be useful in diagnosing neurological disorders that involve primarily one subsystem.

Adult↗
PubMed1985

Patterns of relapse in locally advanced head and neck cancer patients who achieved complete remission after combined modality therapy.

Relapse patterns in patients with locally advanced head and neck cancer who achieved complete remission were evaluated. After combined modality therapy with induction chemotherapy followed by surgery and/or radiotherapy, 71 of 103 patients were clinically free of disease. The 5-year recurrence rate was estimated at 51%, with a 39% local and 26% distant failure rate by 5 years. The factors significantly affecting the relapse patterns were: the site of the primary tumor (those with oral cavity lesions were more likely to fail locally, whereas hypopharynx patients had a higher risk of distant metastases); the type of definitive local treatment (those patients who received surgery and radiotherapy were at lower risk of pure local failure); TN Stage (patients with T4N3 or T3N3 tumor were at higher risk of both local and distant failure); and time to response and presence of oropharyngeal lesions (patients who had a longer period from diagnosis to final complete response [CR] and patients with oropharyngeal primaries were at higher risk for simultaneous local and distant failure). Type of chemotherapy, patient age, tumor differentiation, and response to induction chemotherapy did not significantly influence the patterns of relapse. A combined modality approach with induction chemotherapy, surgery, and/or radiotherapy does not seem to reduce the incidence of distant metastases significantly.

Adult↗
PubMed1985

The antiemetic activity of droperidol administered by intramuscular injection during cisplatin chemotherapy: a pilot study.

The antiemetic activity of escalating doses of droperidol was evaluated in ten patients undergoing chemotherapy with cisplatin regimens. Major antiemetic activity was achieved in five patients, two patients had less nausea and vomiting as compared with prior prochlorperazine therapy, and three patients were refractory to droperidol. No dose-response relationship was observed. Sedation occurred in nine patients, and two patients experienced dystonic reactions. Droperidol is a relatively safe and effective antiemetic for patients undergoing chemotherapy with cisplatin.

Adult↗