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Biomedical subjects

K B Koh

Publications and source records attributed to K B Koh.

At least 19 recordsLinked to original sources
PubMed2000

Elimination of HIV-1 plasmid DNA from virus samples obtained from transfection by calcium-phosphate co-precipitation.

Molecular genetics is a powerful tool to analyze the replication cycle of human immunodeficiency virus type 1 (HIV-1). Culture fluids obtained from HIV-1 plasmid-transfected cells by calcium-phosphate co-precipitation were treated with ethyleneglycol bis (beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) and DNase I to obtain HIV-1 stocks virtually free of input plasmid DNAs. Even after amplification by polymerase chain reaction (PCR), no plasmid DNA was detected in cells following infection with EGTA/DNase I-treated virus samples. This method is particularly useful for the examination of the early replication phase of HIV-1 by PCR.

Calcium↗
PubMed2000

The H9/M8166 tropism of various HIV-1 mutants is determined by distinct cellular factors (review).

We have previously shown that a number of human immunodeficiency virus type 1 (HIV-1) mutants generated in vitro display a replication-defect in a cell-dependent manner. Of the mutants of this category, those of gag, vif, and env mutants do not grow at all in lymphocytic H9 (non-permissive) cells, but quite well in M8166 (permissive) cells. To determine whether the cell-dependent growth of the mutants is functionally related to each other, a number of double mutants were constructed, and monitored for their replication and biochemical property in various cells. The results obtained have indicated that there are multiple cellular factors responsible for the growth phenotype. Together with our previous findings on the host cell-dependent mutants of HIV-1, it is concluded that number of distinct cellular factors are involved in the various steps in HIV-1 replication cycle.

Animals↗
PubMed1999

Psychiatric care for patients with breast cancer.

Psychiatric management of patients with breast cancer, as well as women's emotional reactions to all phases of breast cancer, were reviewed. These patients face two major losses; one is the physical loss of part of the body and a threat to life, and the other is the loss of femininity. The patients are also likely to suffer from various psychiatric problems including anxiety and depression. Oncologists should be alert to each patient's emotional reactions and potential psychiatric problems, and if necessary, should refer them to a psychiatrist. A combination of psychotherapeutic, behavioural, and pharmacologic techniques is available for the care of patients with breast cancer. Psychotherapeutic modalities include individual therapy, family therapy, group therapy, and self-help treatment. The author divided individual therapy into general and specific treatment. General treatment deals with a crisis-intervention and cognitive-behavioral approach, whereas specific treatment deals with issues relevant to patients with breast cancer. Some of the therapeutic processes were illustrated in a case report. These guidelines will contribute to the relief and prevention of emotional suffering stemming from an encounter with the most common form of cancer in women. Also, proper and effective care for patients with breast cancer requires combined use of a variety of therapeutic modalities as well as a multi-disciplinary approach including psychiatric care.

Breast Neoplasms↗
PubMed1998

Emotion and immunity.

Earlier studies have suggested that depression is associated with decreased immune function, but a recent literature review has revealed that a majority of studies reached inconsistent or conflicting conclusions. On the other hand, studies on immune function in anxiety disorders are sparse, and their findings are also inconsistent. Despite a few contradictory results, a clinical level of anxiety seems to reduce immune function, whereas a subclinical level of anxiety seems to enhance immunity. The latter may be a transient phenomenon occurring prior to the downregulation of immune function, reflecting the body's defense to a stressor. Thus, research needs to be conducted to elucidate the relationship between those hormones related to hypothalamic-pituitary-adrenal axis and a variety of immune measures at the subclinical level of anxiety. In addition, to confirm the interaction between emotion and immune function, the effectiveness of treatment with medication and psychotherapy on immunity should be investigated.

Anxiety↗
PubMed1998

Perceived stress, psychopathology, and family support in Korean immigrants and nonimmigrants.

The purpose of this study was to determine the effects of immigration on perceived stress, psychopathology, and family support in Korean immigrants. A total of 105 immigrants and 32 nonimmigrants responded to the questionnaire. The Global assessment of recent stress (GARS) scale as well as anxiety, depression and somatization scales of the symptom checklist-90-revised (SCL-90-R), and the perceived social support scale were used to measure perceived stress, psychopathology and extent and of family support. Immigrants scored significantly higher on the somatization scale than nonimmigrants. However, no significant differences were found in scores on the anxiety and depression scales of SCL-90-R, total GARS scores for family support between the two groups. Immigrants with lower incomes had significantly higher scores on the anxiety, depression and somatization scales as well as total GARS scores than those with higher incomes, whereas the former were significantly lower in family support than the latter. Immigrants with nonprofessional occupations had significantly higher scores on the anxiety and somatization scales and lower scores for family support than those with professional occupations. The extent of satisfaction for family (spouses and children), job and friendship had significantly negative correlations with scores on all three scales of SCL-90-R in immigrants. These results suggest that Korean immigrants had more somatization than nonimmigrants, and that the immigrants' psychopathology, including somatization, could be greatly influenced by income, type of occupation, satisfaction for job, family and friendship.

Adult↗
PubMed1997

Successful closure of a recto-prostatic fistula.

Recto-prostatic fistula is a rare complication of prostatic surgery, occurring usually because surgical planes are not appreciated. We describe a combined abdomino-perineal approach for the repair of a large recto-prostatic fistula with the interposition of omentum and gracilis without formally closing the fistula in layers.

Aged↗
PubMed1996

Beware the undescended testis and abdominal mass.

We report five patients who presented with seminoma of an undescended testis to highlight the importance of dealing with adult cryptorchidism. On the basis of the literature review and our experience, we advocate orchidectomy for post-pubertal cryptorchid patients of any age because follow-up may be difficult, and treatment for the tumour may be unsuccessful.

Adult↗
PubMed1996

Radiological parameters of bleeding renal angiomyolipoma.

Angiomyolipomas are rare tumours of the kidney which have a tendency to bleed. We studied the clinical and radiological features of 11 patients from our institution to identify features which may be predictive of a massive haemorrhage. Tumours more than 6 cm in diameter were found to bleed and the demonstration of pseudoaneurysms on contrast CT scanning was associated with massive haemorrhage. We conclude that large angiomyolipomas should be treated to avoid haemorrhage and the detection of pseudoaneurysms should prompt urgent treatment.

Adult↗
PubMed1996

Spontaneous rupture of renal angiomyolipoma presenting as acute abdomen.

Five cases of renal angiomyolipoma which underwent spontaneous rupture are described. These patients presented as an "acute abdomen" for which the diagnosis was not initially apparent. A high index of suspicion is required to make the diagnosis even with modern imaging techniques. The treatment of these tumours is discussed.

Abdomen, Acute↗
PubMed1996

Intracranial germinoma metastasizing via a ventriculo-peritoneal shunt.

Primary germinomas of the central nervous system carry a good prognosis because of their radiosensitivity. Recurrences are rare and extraneural metastases are even more unusual. One of the possible routes of extraneural spread is via ventriculo-peritoneal shunts which may be required to reduce intracranial pressure. One such case of germinoma metastasizing via a ventriculo-peritoneal shunt is reported. Patients with intracranial germinomas and ventriculo-peritoneal shunts should have close surveillance of their abdomens and may require systemic chemotherapy.

Adult↗
PubMed1995

Testicular torsion.

A retrospective review of 80 patients who underwent scrotal exploration for presumed testicular torsion is presented. Of these, 67 patients were found to have torsion, and the testicular loss rate was 51%. Patients who experienced delays in scrotal exploration of more than 24 h from onset of symptoms had a testicular loss rate of 71%. These delays arose from both hesitation in seeking medical treatment and misdiagnoses. It is emphasized that an acute scrotum in a child or in an adolescent should be explored early to exclude torsion.

Acute Disease↗
PubMed1995

Melioidosis presenting as epididymo-orchitis.

We report a rare case of suppurative epididymo-orchitis caused by Pseudomonas pseudomallei in a 56-year-old male. This is a gram negative bacillus found mainly in tropical zones. Diagnosis was reached by culture of the organisms after drainage of the scrotal abscess, and the patient was treated by a course of oral chloramphenicol 500 mg qid for 6 months.

Burkholderia pseudomallei↗
PubMed1994

Early catheter removal following transurethral prostatectomy--impact on length of hospital stay.

OBJECTIVE: To investigate whether early catheter removal following transurethral prostatectomy (TURP) is safe and whether it has any effect on the length of hospital stay. PATIENTS AND METHODS: Following transurethral prostatectomy 59 patients were randomized into one of two groups: those whose catheter was removed on day 1 after surgery and those whose catheter was removed on day 2. The incidence of complications and the duration of post-operative hospital stay were assessed. RESULTS: Catheter removal on day 1 led to a significantly shorter post-operative hospital stay (2.3 days versus 3.3 days) and did not incur a higher incidence of complications. CONCLUSIONS: Removal of the catheter on the first day following TURP is safe in selected patients and leads to a shorter post-operative hospital stay.

Aged↗