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Biomedical subjects

G L Baker

Publications and source records attributed to G L Baker.

At least 19 recordsLinked to original sources
PubMed1992

Microvascular digit transposition following a two-digit amputation in an infant.

Multiple digit amputations in children demand special consideration to make subsequent hand function optimal. Replanted digits in children have a comparatively lower viability rate, but those that do survive usually go on to excellent function. In this case, an amputated thumb was severely mangled and not suitable for replantation. An amputated index finger was transposed to the thumb position. A six-month postoperative follow-up of the transposed digit confirmed satisfactory joint motion, restored sensibility, and unimpaired digit growth. The 11-month-old infant described is the youngest patient ever reported to have undergone a successful emergency microvascular digit transposition.

Amputation, Traumatic↗
PubMed1992

Superior vena cava syndrome: etiology, diagnosis, and treatment.

Superior vena cava (SVC) syndrome is a critical condition in which an intrathoracic mass lesion compresses the SVC and promotes the development of head and upper body edema and cyanosis. SVC syndrome develops in 10% of patients with a right-sided malignant intrathoracic mass lesion. Diagnostic evaluation and emergency therapy are always necessary to assess and alleviate airway obstruction, cerebral venous hypertension and symptoms secondary to mediastinal compression. Radiation therapy and venous bypass of the obstructed SVC are both used successfully as early treatment. Although radiation therapy to the malignant process may provide initial decompression, a more sustained decrease in venous pressure occurs in patients who also undergo decompressive SVC surgical bypass. SVC bypass should be considered early in the course of patients with profound cerebral or laryngeal edema, patients with extensive thrombosis of the SVC, and in rare patients afflicted with severe venous hypertension and in whom a tissue diagnosis requires a mediastinal exploration.

Adrenal Cortex Hormones↗
PubMed1991

Plasma amino acid concentrations and amino acid ratios in normal adults and adults heterozygous for phenylketonuria ingesting a hamburger and milk shake meal.

Plasma amino acid concentrations were measured and selected amino acid ratios were calculated in 12 normal adults and 12 adults heterozygous for phenylketonuria (PKU) ingesting a hamburger and milk shake meal providing 1 g protein/kg body wt. Plasma concentrations of all amino acids increased significantly over baseline after meal ingestion in both groups, reaching the highest mean values 3-5 h after meal ingestion. Plasma phenylalanine concentrations were significantly higher in heterozygous than in normal subjects both before and at all times after meal ingestion. The absolute increase in plasma phenylalanine concentration over baseline and the area under the plasma phenylalanine concentration-time curve were approximately twice as large in heterozygous as in normal subjects. However, the molar ratio of the plasma phenylalanine concentration to the sum of the plasma concentrations of the other large neutral amino acids did not increase significantly over baseline, but rather decreased.

Amino Acids↗
PubMed1991

Management of arginine monohydrochloride extravasation in the forearm.

We initially observed our patient, who had subcutaneous arginine monohydrochloride extravasation in the volar forearm, until his wound demarcation was complete. After wound demarcation, we proceeded with debridement and partial-thickness skin grafting. Upper extremity function was totally normal 3 months after this therapy. This is the first case report in the literature that describes a child with an arginine monohydrochloride-induced extravasation necrosis.

Amino Acid Metabolism, Inborn Errors↗
PubMed1990

Fasciocutaneous island flap based on the medial plantar artery: clinical applications for leg, ankle, and forefoot.

Soft-tissue deficits over the plantar forefoot, plantar heel, tendo calcaneus, and lower leg are often impossible to cover with a simple skin graft. The previously developed medial plantar fasciocutaneous island flap has been adapted to cover soft-tissue defects over these areas. This fasciocutaneous flap based on the medial plantar neurovascular bundle is capable of providing sensate and structurally similar local tissue. Application of this fasciocutaneous island flap is demonstrated in 12 clinical cases. Successful soft-tissue cover was achieved on the plantar calcaneus (four patients), tendo calcaneus (four patients), lower leg (two patients), and plantar forefoot (two patients). Follow-up ranged from 6 months to 5 years. All flaps were viable at follow-up. Protective sensation was present in 11 of 12 flaps evaluated at 6 months. In addition, all 11 patients were able to ambulate in normal footwear. The medial plantar island flap seems to be more durable than a skin graft, and the donor site on the non-weight-bearing instep is well tolerated. This study demonstrates that the medial plantar fasciocutaneous island flap should be considered as another valuable tool in reconstructive efforts directed at the plantar forefoot, plantar heel, posterior ankle, and lower leg.

Adolescent↗
PubMed1989

Repeated ingestion of aspartame-sweetened beverage: effect on plasma amino acid concentrations in individuals heterozygous for phenylketonuria.

It has been suggested that excessive use of aspartame (APM) (N-L-alpha-aspartyl-L-phenylalanine methyl ester) might grossly elevate plasma aspartate and phenylalanine concentrations in individuals heterozygous for phenylketonuria (PKUH). In study 1 six adult PKUH (three males; three females) ingested three successive 12-oz servings of beverage at 2-h intervals. The study was carried out in two parts in a randomized crossover design. In one arm the beverage was not sweetened. In the other the beverage provided 10 mg APM/kg body weight per serving. The addition of APM to the beverage did not significantly increase plasma aspartate concentration but did increase plasma phenylalanine levels 2.3 to 4.1 mumol/dL above baseline values 30 to 45 min after each dose. The high mean plasma phenylalanine level after repeated APM dosing (13.9 +/- 2.15 mumol/dL) was slightly, but not significantly, above the normal postprandial range for PKUH (12.6 +/- 2.11 mumol/dL). In study 2 six different adult PKUH ingested beverage providing 30 mg APM/kg body weight as a single bolus. The high mean plasma phenylalanine concentration and the phenylalanine to large neutral amino acid ratio were significantly higher when APM was ingested as a single bolus than when ingested as a divided dose.

Adult↗
PubMed1989

Partitioning of ventilation between nose and mouth: the role of nasal resistance.

We have examined the relationship between nasal resistance (Rna) and the distribution of ventilation between the nose and mouth in 10 normal breathing children and 15 children who met clinical criteria of mouth breathing. We studied Rna by posterior rhinometry. We used a face mask divided into separate oral and nasal chambers to measure oral and nasal components of ventilation. Each chamber of the mask was connected to a separate pneumotachograph. We measured oral and nasal tidal volumes (VTna) by integration of the oral and nasal flow, and calculated the total tidal volume (VTtot) by summing the oral and nasal components. The nasal fraction of ventilation (F-VTna) was calculated by dividing VTna by VTtot. We found a weak inverse correlation between Rna and F-VTna, but eight of 25 children did not breathe as one might predict on the basis of Rna, and eight of 15 children who appeared to be mouth breathers actually breathed through the nose. We administered a vasoconstricting nasal spray and a placebo nasal spray to the children and, although Rna changed significantly, we observed no change in the distribution of flow between the nose and mouth. In summary we found that clinical criteria of mouth breathing do not accurately identify children who actually breathe mainly through the mouth. Moreover Rna is only a weak predictor of the pattern of breathing; hence other factors may be important determinants of the distribution of flow between the nose and mouth.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1988

Repeated ingestion of aspartame-sweetened beverage: effect on plasma amino acid concentrations in normal adults.

Aspartame (APM) is a dipeptide sweetener (L-aspartyl-L-phenylalanine methyl ester). It has been suggested that excessive use of the product might elevate plasma aspartate and phenylalanine concentrations. Eight normal adults (four male, four female) ingested three successive 12-oz servings of APM-sweetened beverage at two-hour intervals. The study was carried out in two parts in a randomized cross-over design. In one study the beverage was not sweetened. In the other, the beverage provided 10 mg APM/kg body weight per serving. Plasma amino acid concentrations were measured throughout the six-hour study period. The addition of APM to the beverage had no significant effect on plasma aspartate concentration. APM addition did increase plasma phenylalanine levels 1.64 to 2.05 mumol/dL above baseline values (5.09 +/- 0.82 mumol/dL) 30 to 45 minutes after each dose. However, plasma phenylalanine levels did not exceed normal postprandial values at any time. The data indicate ready metabolism of APM's amino acid content when administered at levels likely to be ingested by individuals who are heavy users of such beverages.

Adult↗
PubMed1987

Malignancy following treatment of rheumatoid arthritis with cyclophosphamide. Long-term case-control follow-up study.

A long-term retrospective case-control study was performed comparing 119 patients with rheumatoid arthritis treated with cyclophosphamide and 119 matched control patients with rheumatoid arthritis not treated with cyclophosphamide to determine the risk of subsequent malignancy. Thirty-seven malignancies were detected in 29 cyclophosphamide-treated patients, while 16 malignancies were found in 16 control patients (p less than 0.05) during a mean follow-up period of more than 11 years. Urinary bladder cancer (six cyclophosphamide-treated patients, no control patients) and skin cancer (eight cyclophosphamide-treated patients, no control patients) were identified as differing statistically between the groups, and hematologic malignancy (five cyclophosphamide-treated patients, one control patient) showed a similar trend. Survival analysis indicated that the rate of development of malignancy in the cyclophosphamide-treated patients was significantly greater than in the control patients at six years following drug initiation, and that this increased rate persisted even at 13 years (p less than 0.01). Of the many risk factors evaluated, mean total cyclophosphamide dose and duration and tobacco use were significantly increased in patients in whom cancer subsequently developed. These long-term complications must be considered seriously when cyclophosphamide or other cytotoxic drugs are initiated for the treatment of rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1987

Plasma amino acid concentrations in normal adults ingesting aspartame and monosodium L-glutamate as part of a soup/beverage meal.

We tested the hypothesis that ingestion of monosodium L-glutamate with aspartame produces a marked increase in plasma glutamate and aspartate concentrations. Twelve normal adults (6 males, 6 females) ingested three different soup/beverage meals in a balanced Latin square design. One meal (A) provided no aspartame (APM) or monosodium L-glutamate (MSG); a second (B) provided 50 mg MSG/kg body weight; while the third (C) provided 50 mg MSG and 34 mg APM per kg body weight. Plasma glutamate (Glu) concentrations were not significantly affected by meal A but increased significantly after meals B and C (no significant difference between B and C). Plasma aspartate (Asp) concentrations were not significantly affected by meal A but increased significantly after meals B and C (values significantly higher after meal C than meal B). Plasma Glu + Asp concentrations were not significantly affected by meal A but increased significantly from a mean (+/- SD) baseline value of 5.64 +/- 2.62 mumol/dL to high mean values of 23.1 +/- 7.29 and 26.8 +/- 9.74 mumol/dL after ingestion of meals B and C, respectively (no significant difference between meals B and C). Similarly, the area under the plasma Glu + Asp concentration-time curve did not differ significantly between meals B and C (624 +/- 197 v 763 +/- 277 mumol/dL x min, respectively). Peak plasma Glu + Asp concentrations for each subject (ignoring time) were also examined. The mean peak plasma Glu + Asp concentrations were 7.39 +/- 2.77, 23.0 +/- 6.61, and 27.3 +/- 9.07 mumol/dL, respectively after meals A, B, and C.

Adult↗
PubMed1987

Pasteurella multocida polyarticular septic arthritis.

Pasteurella multocida is an unusual cause of septic arthritis with most patients having underlying joint damage or altered host defenses. We report 2 cases of polyarticular sepsis with this bacteria. Predisposing factors in our patients included alcoholic cirrhosis, end stage renal disease and metastatic malignancy. Heightened awareness of this organism's involvement in polyarticular septic arthritis in the immunocompromised patient is emphasized.

Arthritis, Infectious↗
PubMed1986

Effect of sucrose ingestion on plasma glutamate concentrations in humans administered monosodium L-glutamate.

Plasma glutamate concentrations in human subjects are markedly lower when monosodium L-glutamate (MSG) is ingested in consomme with starch than when ingested in consomme alone. This study investigated whether sucrose had a similar effect. Six normal adult subjects (three male, three female) ingested two servings of beef consomme each providing 50 mg MSG/kg body weight in a randomized crossover design. One serving of consomme contained no added carbohydrate; the other provided 0.5 g sucrose/kg body weight. Ingestion of the consomme without sucrose significantly (p less than 0.05) increased the mean plasma glutamate concentration from baseline (4.44 +/- 0.97 mumol/dl) to a peak value of 18.1 +/- 6.99 mumol/dl 30 min after dosing. The area under the plasma glutamate concentration-time curve was 553 +/- 238 mumol/dl X min. When the consomme contained 0.5 g sucrose/kg body weight, both the mean peak plasma glutamate concentration (5.48 +/- 2.19 mumol/dl) and the area under the curve (105 +/- 46 mumol/dl X min) were significantly lower. These data confirm that metabolizable carbohydrate has a significant effect on plasma glutamate concentration response after MSG loading.

Administration, Oral↗
PubMed1986

Plasma glutamate concentrations in 1-year-old infants and adults ingesting monosodium L-glutamate in consommé.

This study tested the hypothesis that infants metabolize glutamate more slowly than adults. Eight 1-yr-old infants ingested 160 ml of a beef consommé providing monosodium L-glutamate at 0, 25, and 50 mg/kg body weight. Plasma glutamate and aspartate concentrations were measured sequentially for the next 2 h. The results were compared to values noted in nine adult subjects ingesting equivalent doses of monosodium L-glutamate in consommé. In adults, mean (+/- SD) peak plasma glutamate concentrations were 5.59 +/- 1.56, 10.2 +/- 2.08, and 17.0 +/- 8.06 mumol/dl, respectively; the area under the plasma glutamate concentration time curves were 96 +/- 42, 257 +/- 80, and 442 +/- 303 mumol/dl X min, respectively. In infants, the mean (+/- SD) peak plasma glutamate concentrations were 6.94 +/- 1.43, 10.6 +/- 2.36, and 12.0 +/- 1.16 mumol/dl, respectively; the plasma glutamate area under the curve values were 47 +/- 28, 191 +/- 85, and 358 +/- 105 mumol/dl X min, respectively. The data indicate that the plasma glutamate concentration response in 1-yr-old infants ingesting MSG at these glutamate doses is no higher than values observed in adult subjects.

Administration, Oral↗
PubMed1985

Plasma glutamate concentrations in adult subjects ingesting monosodium L-glutamate in consomme.

The effect of MSG ingestion in consomme on the plasma glutamate concentration response was studied in normal adult subjects. In the first study nine subjects ingested three different consomme servings (providing 0, 25 and 50 mg/kg body weight MSG) in a Latin square design. Plasma glutamate concentrations were not significantly increased over baseline (3.69 +/- 1.08 mumol/dl) when no added MSG was present. However, mean peak plasma glutamate levels increased proportional to dose when MSG was added (10.2 +/- 2.00 and 17.0 +/- 8.06 mumol/dl at 25 and 50 mg/kg body weight respectively). Since six of the nine subjects in this study reported an idiosyncratic symptom response when tested with MSG at 150 mg/kg body weight, nine additional subjects were also studied. They ingested consomme providing MSG at 0 and 50 mg/kg body weight. No significant differences in plasma amino acid responses were noted between the two groups of subjects.

Adult↗
PubMed1985

Effect of starch ingestion on plasma glutamate concentrations in humans ingesting monosodium L-glutamate in soup.

Plasma glutamate concentrations in human subjects are markedly lower when monosodium L-glutamate is ingested in a water solution containing partially hydrolyzed starch than when ingested in water alone. This study was carried out to investigate whether starch ingested as crackers had a similar effect. Eight normal adult subjects (four male, four female) ingested three servings of a beef consommé providing 50 mg/kg body weight monosodium L-glutamate. One serving was consommé alone, the other two were accompanied by sufficient crackers to provide 0.25 or 0.5 g starch per kilogram body weight, respectively. Ingestion of consommé containing glutamate significantly increased the mean plasma glutamate concentration above baseline to a mean peak value 30 min later. The peak after consumption of 0.5 g starch per kilogram body weight, but not 0.25 g/kg body weight, was significantly lower than when consommé alone was ingested. These data indicate that simultaneous ingestion of metabolizable carbohydrate with glutamate has a marked effect on the plasma glutamate response and indicate that the threshold value for carbohydrate is greater than 0.25 g/kg body weight.

Adult↗
PubMed1985

Oxygen free radical induced damage in kidneys subjected to warm ischemia and reperfusion. Protective effect of superoxide dismutase.

Superoxide anion free radical (O2-.) has been implicated in the pathogenesis of tissue injury consequent to ischemia/reperfusion in several different organs, including heart and bowel. Superoxide dismutase (SOD), an enzyme free radical scavenger specific for O2-., has been used successfully to protect these organs from structural damage during reoxygenation of ischemic tissue. It has been suggested that the catalytic action of xanthine oxidase in injured tissue is an important source of O2-. during reoxygenation. In order to evaluate the potential of SOD to protect against kidney damage resulting from transient ischemia followed by reperfusion with oxygenated blood, a model of warm renal ischemia was studied. LBNF1 rats underwent right nephrectomy and occlusion of the left renal artery for 45 minutes. Survival in the group of ischemic untreated rats (N = 30) was 56% at 7 days and serum creatinine was greatly elevated (p less than 0.01) in rats remaining alive over the full 7-day period. In strong contrast to these results, all of the animals treated with SOD before reperfusion (N = 18) were alive after 7 days similar to sham operated control rats (N = 8). Serum creatinine in the SOD treated rats was significantly elevated only to postoperative day 3 and thereafter returned to normal. Rats treated with inactive SOD (N = 4) or SOD before ischemia (N = 4) had decreased survival rates compared to ischemic untreated animals and prolonged elevation of serum creatinine. When the ischemia time was extended to 60 minutes, only 19% of the untreated animals (N = 16) survived at 7 days whereas nearly 60% of the SOD-treated animals survived (N = 19). Serum creatinine was greatly elevated during the full 7-day observation period in all surviving rats in the untreated ischemic group, whereas serum creatinine returned to normal (p less than 0.05) after 4 days in the surviving rats treated with SOD. To test whether the action of xanthine oxidase contributed to the kidney damage after reoxygenation, 45 min. ischemic rat kidneys were treated with allopurinol. All of the animals treated with allopurinol (N = 12) were alive at 7 days. Serum creatinine values returned to normal after the episode of ischemia and reperfusion but more slowly than after SOD treatment. Histologic evaluation of kidney tissue taken from animals after ischemia alone showed extensive renal tubular damage, which was essentially absent in kidneys from SOD-treated animals.(ABSTRACT TRUNCATED AT 400 WORDS)

Allopurinol↗
PubMed1985

Ankylosis of the temporomandibular joint from psoriatic arthritis.

A review of 27 cases of temporomandibular joint arthritis in patients with psoriasis reveals the main pathologic features to be condylar erosions, condylar osteoporosis, calcification of the articular disc, and subchondral cyst formation. We present another pathological process, temporomandibular joint bony ankylosis in a patient with psoriasis. Surgical management consisted of a high condylectomy, with a silastic implant to maintain the vertical dimension of the ramus. A very good functional result was obtained and 21/2 years later her incisive distance is 44 mm.

Adult↗