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Biomedical subjects

M Goh

Publications and source records attributed to M Goh.

At least 19 recordsLinked to original sources
PubMed2000

Characterizing rice lesion mimic mutants and identifying a mutant with broad-spectrum resistance to rice blast and bacterial blight.

Many plant mutants develop spontaneous lesions that resemble disease symptoms in the absence of pathogen attack. In several pathosystems, lesion mimic mutations have been shown to be involved in programmed cell death, which in some instances leads to enhanced disease resistance to multiple pathogens. We investigated the relationship between spontaneous cell death and disease resistance in rice with nine mutants with a range of lesion mimic phenotypes. All nine mutations are controlled by recessive genes and some of these mutants have stunted growth and other abnormal characteristics. The lesion mimics that appeared on the leaves of these mutants were caused by cell death as measured by trypan blue staining. Activation of six defense-related genes was observed in most of the mutants when the mimic lesions developed. Four mutants exhibited significant enhanced resistance to rice blast. One of the mutants, spl11, confers non-race-specific resistance not only to blast but also to bacterial blight. The level of resistance in the spl11 mutant to the two pathogens correlates with the defense-related gene expression and lesion development on the leaves. The results suggest that some lesion mimic mutations in rice may be involved in disease resistance, and cloning of these genes may provide a clue to developing broad-spectrum resistance to diverse pathogens.

Bacteria↗
PubMed2000

Quality improvement in the healthcare industry: some evidence from Singapore.

Presents an exploratory field research on all hospitals in Singapore, highlighting the different routes hospitals have adopted in pursuing their corporate quality journey for the new millennium. In general, both continuous improvement and innovation-based approaches have generated cost and time savings and helped to streamline work processes. However, the initial survey results show that innovation-based programs require a longer time frame for implementation, are more prone to resistance to change and suffer from program failure. Also, large hospitals and public hospitals are more inclined to implement innovation based approaches while medium-sized hospitals tend to use continuous improvement as a medium for quality improvement.

Health Services Research↗
PubMed2000

Role of p53 in cell cycle regulation and apoptosis following exposure to proteasome inhibitors.

In this study, we explored what effect inhibitors of the 26S proteasome have on cell cycle distribution and induction of apoptosis in human skin fibroblasts and colon cancer cells differing in their p53 status. We found that proteasome inhibition resulted in nuclear accumulation of p53. This was surprising because it is thought that the degradation of p53 is mediated by cytoplasmic 26S proteasomes. Nuclear accumulation of p53 was accompanied by the induction of both p21WAF1 mRNA and protein as well as a decrease in cells entering S phase. Interestingly, cells with compromised p53 function showed a marked increase in the proportion of cells in the G2-M phase of the cell cycle and an attenuated induction of apoptosis after proteasome inhibition. Taken together, our results suggest that proteasome inhibition results in nuclear accumulation of p53 and a p53-stimulated induction of both G1 arrest and apoptosis.

Acetylcysteine↗
PubMed1999

Almost totally tubeless percutaneous nephrolithotomy: further evolution of the technique.

BACKGROUND AND OBJECTIVES: There is renewed interest in the concept of foregoing placement of the postoperative nephrostomy tube (PNT) after percutaneous nephrolithotomy (PCNL) with the intent of reducing postoperative discomfort and hospital stay. We have omitted the PNT and placed an internal ureteral stent or externalized ureteral catheter after PCNL in selected patients. We reviewed our experience in order to assess the efficacy and safety of this practice. PATIENTS AND METHODS: Primary PCNL was performed in 26 renal units in 21 patients (5 bilateral PCNL, 4 of which were simultaneous) by one surgeon at the University of Michigan and the Ann Arbor Veterans Affairs Medical Center. A postoperative nephrostomy tube was placed if the stone burden was >3 cm, more than one access site was used, the renal anatomy was obstructive, significant bleeding or perforation was noted, or a second look was required. RESULTS: No PNT was placed in 10 renal units in 8 patients (no-PNT group). In six no-PNT kidneys, internal ureteral stents were used, and in four, externalized ureteral stents were placed for 1 to 2 days. The mean stone size in the PNT and no-PNT patients was 3.0 and 1.8 cm, respectively. Of the 16 kidneys in the PNT group, 4 were initially eligible for omission of PNT, but a PNT was placed because of bleeding or other access-related problem. All patients were rendered stone free except for three (one PNT and two no-PNT) patients, who each had a fragment < or =4 mm. Omission of PNT placement resulted in decreased mean length of stay (2.3 days in the no-PNT group v 3.6 days in the PNT group). There were four complications, all managed with delayed stenting (one in a no-PNT patient and the remaining three in the PNT group). CONCLUSION: Omission of PNT placement in selected patients may reduce morbidity without compromising efficacy and safety, but further study is needed.

Female↗
PubMed1999

A quality roadmap of a restructured hospital.

This paper presents a quality roadmap of a restructured hospital. Specifically, a case study is showcased to reveal how a FOCUS-PDCA model is applied to the Central Portering Services (CPS) within a restructured hospital, to provide better service to other departments within the hospital who can then in turn value add to the patient care delivery chain. The preliminary results suggest that implementers of quality and service improvement programmes using the FOCUS-PDCA approach should note some of the key implementation difficulties. These difficulties occur at all levels and include issues relevant to change management, process improvement programmes, accessibility to data, communication and judicious execution of the change process.

Hospital Restructuring↗
PubMed1998

Serum antibodies specific to CD outer membrane protein of Moraxella catarrhalis, P6 outer membrane protein of non-typeable Haemophilus influenzae and capsular polysaccharides of Streptococcus pneumoniae in children with otitis media with effusion.

We measured the levels of serum IgG antibodies to CD outer membrane protein of Moraxella catarrhalis, P6 outer membrane protein of non-typeable Haemophilus influenzae and capsular polysaccharides of Streptococcus pneumoniae in 168 children with otitis media with effusion (OME) who were followed prospectively, using ELISA. Serum IgG antibodies to CD, P6 and pneumococcal capsular polysaccharides were detected in all samples. The anti-pneumococcal polysaccharides antibody level was highest, followed by the anti-P6 antibody level and anti-CD antibody was lowest (median:interquartile ranges were 45.9:19.1-100 microg/ml, 15.6:9.70-23.2 microg/ml and 1.06:0.73-1.87 microg/ml, respectively). In children aged 0-6 years, there were positive correlations among the antibody levels (anti-CD vs anti-P6, r=0.325, p <0.001; anti-CD vs anti-polysaccharide, r=0.397, p <0.0001; anti-P6 vs anti-polysaccharide, r=0.175, p=0.057). However, no relationship was seen in children aged 7-15 years. Children were classified according to severity of OME during the 1-year follow-up. In children aged 0-6 years, the severity of OME correlated inversely with the levels of anti-CD antibody (r=-.23, p=0.012), of anti-P6 antibody (r=-0.292, p=0.0015), and of anti-pneumococcal polysaccharides antibody (r=-0.25, p=0.0064). However, no correlation was found between antibody levels and severity of OME in children aged 7-15 years. These data suggest that persistence and/or recurrence of OME may be due to an insufficient serum antibody response to middle ear pathogens in young children.

Adolescent↗
PubMed1997

Autologous blood donation prior to anatomical radical retropubic prostatectomy: is it necessary?

OBJECTIVES: To determine if autologous blood donation prior to anatomical radical retropubic prostatectomy, given current improvements in surgical technique, is necessary. METHODS: The medical records of 200 consecutive patients undergoing radical retropubic prostatectomy for clinically localized prostate cancer were reviewed with regard to (1) preoperative hematocrit (HCT); (2) estimated blood loss (EBL); (3) postoperative HCT prior to discharge; (4) number of units of autologous blood donated; and (5) number of units of autologous and homologous blood transfused. In addition, the charges associated with autologous blood donation were determined via telephone interview with 14 blood donation centers across the United States. RESULTS: Overall, 189 patients (95%) did not require a homologous blood transfusion. Sixty-four patients (32%) donated autologous units and 136 patients (68%) did not. Of the patients who had donated, only 17 (27%) received their blood back, and none (0%) received any homologous blood. Eleven (8%) of the 136 nondonors received a blood transfusion. The autologous donors, in comparison with nondonors, were found to have a significantly lower preoperative HCT (mean +/- standard deviation: 40 +/- 4.0% versus 42 +/- 2.9%, P < 0.05). However, there was no statistically significant difference in the mean EBL between the two groups, autologous donors versus nondonors (771 +/- 370 versus 737 +/- 425 cc, P = 0.23). The autologous donors had a smaller mean change in HCT versus the nondonors (-9.3 +/- 5.1% versus -11.2 +/- 4.4%, P < 0.05), reflecting an increased willingness to transfuse patients who have autologous units available. With regard to cost, patients, on average, can expect to be charged as much as $745 per unit of autologous blood donated. CONCLUSIONS: These findings suggest that preoperative blood donation prior to radical prostatectomy may not be necessary, because 95% of the patients did not require a homologous blood transfusion. In addition, autologous blood donation can be associated with substantial costs in both time and money. Thus, autologous donation should be left as an option for the patient and should not be considered routine practice.

Adult↗
PubMed1997

Percutaneous nephrolithotripsy in the morbidly obese patient.

From 1989 to 1995, 530 patients underwent percutaneous nephrolithotripsy, of which 93 were identified as morbidly obese. A retrospective study was performed comparing results of nephrolithotripsy in patients with near normal ideal body weight versus those patients considered morbidly obese. Outcome parameters measured included size, configuration, and number of calculi, location and number of access sites required, stone-free rates, operative time, number of ancillary procedure, hospital stay, and complications. Stone number was similar between the normal weight and morbidly obese groups; however, the morbidly obese group had smaller stones treated percutaneously. Operative time was similar between the two groups if a single access was required, but then was significantly higher in the morbidly obese group if multiple access sites were necessary. Stone-free rates were not statistically different between normal weight versus obese patients (89% vs. 82%). However, hospital stay was longer (3.5 days vs. 4.4 days) and the overall rate of complications was higher (16% vs. 37%) in the morbidly obese group compared to normal weight group.

Adult↗
PubMed1991

[Successful surgical treatment of a case of corrected transposition in situs inversus with associated anomalies].

A 33-year-old female with corrected transposition (situs inversus) with ventricular septal defect (VSD), atrial septal defect (ASD), and pulmonary stenosis (valvular and subvalvular) was operated successfully. Closure of ASD and infracristal VSD was performed through right atrial approach. In order to get complete exposure of VSD, a part of anterior leaflet of mitral valve was detached temporally. An external conduit was interposed between the morphologic left ventricle and the main pulmonary artery to relieve pulmonary stenosis. Postoperative course was uneventful except a transient complete heart block for a day. Several technical aspects of the radical operation were discussed including VSD closure method to avoid damaging the atrioventricular conducting tissues and reconstructive procedure of morphological left ventricular outflow.

Abnormalities, Multiple↗
PubMed1988

The effects of acute and chronic growth hormone (GH) administration on GH secretion in patients with idiopathic GH deficiency.

The effect of acute and chronic administration of GH on plasma GH responses to GHRH were studied in patients with idiopathic GH deficiency (GHD). Nine untreated GHD patients, 1 untreated patient with postoperative craniopharyngioma, and 7 normal short children were given synthetic human GHRH-44 (100 micrograms, iv) injection before and 2 days after being given a single dose of 4 IU biosynthetic methionyl human GH (mGH), im. Twelve GHD patients, who had been treated with 0.31-0.48 IU/kg.week pituitary-derived hGH (pdGH), im, for 8-79 months, were given GHRH 2 and 14 days after a final injection of 4 IU pdGH. Three other GHD patients were given GHRH before and after 2 yr of pdGH therapy (0.35-0.39 IU/kg.week). The GHRH-induced GH response (max delta GH) was significantly inhibited after mGH administration in the 9 untreated GHD patients [2.7 +/- 0.3 (+/- SE) vs. 4.7 +/- 0.6 micrograms/L; P less than 0.01]. The patient with secondary GH deficiency also had a marked reduction in her peak plasma GH value after mGH administration (from 32.0 to 11.7 micrograms/L). Similarly, the mean max delta GH response in the 7 normal short children was significantly inhibited by prior mGH injection (max delta GH, 12.7 +/- 2.0 vs. 28.8 +/- 4.8 micrograms/L; P less than 0.01). In the 12 treated GHD patients the GHRH-induced GH response on the 2nd day after discontinuation of pdGH therapy was significantly lower than that on the 14th day (max delta GH, 3.4 +/- 1.2 vs. 6.9 +/- 1.6 micrograms/L; P less than 0.02). In the 3 GHD patients who were studied before and after 2 yrs of pdGH therapy, the plasma GH responses were similar. In each group, plasma somatomedin-C levels on the second day after GH administration were slightly but not significantly higher than those before or 14 days after the administration. The GH responses to GHRH given on 2 occasions at 7- to 14-day intervals in individuals not receiving GH were similar in both 9 normal children and 10 GHD patients. These results indicate that acute GH administration inhibits somatotroph function in GHD patients, but chronic GH therapy does not cause irreversible damage to the somatotrophs. The acute inhibition of GHRH-induced GH release after GH administration is more likely due to direct and indirect pituitary inhibition by somatomedin-C and/or somatostatin than decreased GHRH secretion.

Adolescent↗
PubMed1988

The spectrum of GH responses to GHRH and somatostatin in patients with acromegaly.

Plasma GH responses to GHRH and somatostatin were examined in 43 patients with active acromegaly. Thirty-two of these patients showed GH increases 50% above the basal values in response to at least 1 of 3 stimuli (TRH, LHRH, arginine) (categorized as group I). The remaining 11 patients showed no response to any of the stimuli (categorized as group II). Following somatostatin infusion, group I (n = 31) showed significantly greater GH suppression than group II (n = 11) from 30 to 90 min (p less than 0.05-0.01). In addition, plasma GH responses to GHRH at 15 and 30 min was also greater in group I (n = 12) than in group II (n = 5) (p less than 0.05 & 0.01). There was a positive correlation between the log value of the peak GH after GHRH and the maximal % decrement after somatostatin (r = 0.64, p less than 0.02). However there were no differences in the responses of normal thyrotrophs (TSH) to TRH between the two groups. These results indicate that there are two types of acromegaly, i.e., one is more responsive and another is less responsive to either non-specific (TRH & LHRH) or specific GH stimulations (GHRH & somatostatin).

Acromegaly↗
PubMed1987

Growth hormone inhibitory and stimulatory actions of L-dopa in patients with acromegaly.

It is not clear whether dopamine (DA) has a central stimulating activity on GH secretion in patients with acromegaly, as it does in normal subjects. To clarify this, we compared the GH inhibitory potencies of DA, which does not cross the blood-brain barrier (BBB), and L-dopa or bromocriptine, which do cross the BBB, in 23 patients with acromegaly. Further, we examined the central effects of L-dopa after selectively blocking peripheral (median eminence and pituitary) DA receptors with domperidone (a DA D2 receptor blocker which does not cross the BBB). After the administration of DA (5 micrograms/kg X min, iv, for 90 min), L-dopa (500 mg, orally), or bromocriptine (2.5 mg, orally), the mean plasma GH decrease was greatest after DA [maximum decrement, 71.9 +/- 3.8% (+/- SEM); n = 21] compared to L-dopa (44.1 +/- 5.6%; n = 23; p less than 0.001) or bromocriptine (58.9 +/- 5.0%; n = 20; p less than 0.02). Eleven of these patients received a single infusion of domperidone (0.22 mg/min, iv, for 180 min) or a combination of domperidone and L-dopa. Mean plasma GH levels did not change during domperidone alone. However, plasma GH levels in these patients increased significantly when L-dopa was administered 30 min after the start of domperidone infusion (vs. control study: at 90 min, 137.3 +/- 10.8% vs. 100.2 +/- 3.9%, p less than 0.01; at 120 min, 138.8 +/- 19.7% vs. 106.5 +/- 3.1%, p less than 0.05). In contrast, one patient who had a distinct plasma GH increase in response to the domperidone-L-dopa test had no increase in plasma GH when given L-dopa 30 min after the start of a sulpiride infusion (DA D2 receptor blocker which crosses the BBB; 1.1 mg/min, iv, for 180 min). Unlike GH, plasma PRL responses to domperidone infusion were not modified by the additional administration of L-dopa. These results suggest that in acromegaly, DA has not only direct suppressive effects on the pituitary tumor somatotrophs, but also indirect stimulatory effects via the hypothalamus; therefore, the hypothalamic GH-releasing system is not entirely suppressed by excessive tumor GH secretion.

Acromegaly↗
PubMed1987

Plasma GH responses to GHRH and other provocative stimuli in idiopathic GH deficiency with or without abnormal delivery.

Seventeen patients with idiopathic growth hormone deficiency (GHD) were divided into two groups: one has no perinatal abnormalities (group A, n = 7) and the other has perinatal abnormalities, i.e. breech delivery and asphyxia (group B, n = 10). To see whether there are any differences in hypothalamo-pituitary dysfunctions in the two groups, the pituitary growth hormone (GH) reserve was examined. After 100 micrograms of synthetic growth hormone releasing hormone (GHRH) injection, group A showed a much higher peak values compared to group B (mean +/- S.E.: 16.1 +/- 3.5 ng/ml vs. 3.6 +/- 0.7 ng/ml, p less than 0.01), although there were no differences in their baseline GH values. In addition, plasma GH responses to arginine and L-dopa, which were performed at the diagnosis of GHD, were also greater in group A than group B (mean peak value: arginine, 3.4 +/- 0.5 ng/ml vs 1.8 +/- 0.5 ng/ml, p less than 0.05; L-dopa, 3.2 +/- 0.7 ng/ml vs. 1.3 +/- 0.2 ng/ml, p less than 0.01). There were no significant differences in the bone ages in the two groups, but bone age to chronological age ratio and pubertal development were significantly lower in group B. High frequency of primipara was observed in group B (7/10) compared to group A (2/7). These results indicate that pituitary GH reserve is much impaired in GHD with abnormal delivery compared to that without abnormal delivery, probably depending on the irreversible hypothalamo-pituitary damages due to prolonged anoxic state during the delivery. Especially, such risks seems to be high when cases of breech presentation are delivered from primipara mothers.

Adolescent↗