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Biomedical subjects

M G Thomas

Publications and source records attributed to M G Thomas.

At least 127 records · Page 7Linked to original sources
PubMed1992

Neurological disease in patients with human immunodeficiency virus infection.

We followed prospectively all patients with HIV infection admitted to the infectious diseases ward at Auckland Hospital over a seven month period. Neurological manifestations of HIV infection were the primary reason for admission in 18 of the 55 patients (33%). Diagnoses were usually presumptive, based on history, clinical findings, radiological appearances and response to empirical therapy. Eight patients had cerebral toxoplasmosis, three primary cerebral lymphoma, two cytomegalovirus retinitis, two HIV neuropathy, one cryptococcal meningitis, one HIV encephalopathy, and one HIV meningitis. Another patient with HIV infection was admitted to the neurology ward at Auckland Hospital with HIV myelopathy during the same seven month period. The median survival of the patients treated for presumptive toxoplasmosis was 7.5 months. Only two patients had not developed AIDS, one having HIV meningitis and the other HIV myelopathy, and in both, symptoms resolved spontaneously with no relapse at one year follow up. The spectrum of neurological manifestations of HIV infection is wide. Investigations to determine the most likely diagnosis are indicated and specific therapy may lead to both excellent palliation and prolonged survival.

HIV Infections↗
PubMed1992

Vitamin D and its metabolites inhibit cell proliferation in human rectal mucosa and a colon cancer cell line.

Like calcium, vitamin D may protect against colorectal neoplasia as it reduces epithelial cell proliferation and induces differentiation. Although its therapeutic use is limited by its effects on calcium metabolism, analogues such as calcipotriol produce little hypercalcaemia. Stathmokinetic and immunohistochemical techniques were used to study the effect of 1,25 (OH)2 D3 and its analogues on cell proliferation in human rectal mucosa and a colon cancer cell line. Paired sigmoidoscopic biopsy specimens were obtained from 17 control patients and five patients with familial adenomatous polyposis. Explants were established in organ culture, with or without the addition of vitamin D. Proliferation was assessed using (1) metaphase arrest to determine the crypt cell production rate (CCPR) and (2) Ki-67 monoclonal antibody directed against an antigen present in proliferating cells. 1,25 (OH)2 D3 in concentrations of 1 microM-100 pM (10(-6)-10(-10) M) reduced the CCPR (cells/crypt/hour) from 4.74 to 2.15-2.67 (p < 0.001), and the Ki-67 labelling index from 7.28-3.74 (p < 0.01). Likewise, vitamin D2, 10 nM (10(-8) M) reduced the CCPR from 4.74-2.74 (p < 0.05) and calcipotriol from 4.86-2.38 (p < 0.05). In familial adenomatous polyposis patients 1,25 (OH)2 D3 100 pM (10(-10) M) halved the CCPR from 8.75-4.22. Calcipotriol (10(-5) M to 10(-9) M) produced a clearcut dose response inhibition of HT-29 cell growth. Thus, vitamin D and its metabolites inhibit proliferation in normal and premalignant rectal epithelium and suppress growth in a colorectal cancer cell line.

Adenomatous Polyposis Coli↗
PubMed1991

HIV-1 infection status in two HIV-1 antibody positive infants determined using the polymerase chain reaction.

The HIV-1 infection status of two HIV-1 antibody positive infants born to HIV-1 infected mothers was determined using the polymerase chain reaction. HIV-1 genomic sequences were not detected in the white blood cells of either infant suggesting that they were not infected. HIV-1 genomic sequences were detected in the white blood cells of the mothers of both infants and in cells from the one surviving father. These results confirm the value of the PCR detection method for assessing the HIV-1 infection status of infants born to HIV-1 antibody positive mothers.

Female↗
PubMed1991

Antibiotic restriction policies in public hospitals.

We surveyed annual expenditure on antimicrobial agents and the use of antimicrobial restriction policies. Restriction policies were in use in 25 of 27 of the hospitals surveyed. Restrictions on the use of antimicrobials were extended into specialty intensive care or haematology units in only 13 of 20 hospitals which had such units. Antimicrobial restriction policies were, for the most part, similar amongst the hospitals surveyed. Use of restriction policies within specialist units was associated with reduced total hospital antibiotic expenditure per bed per year.

Anti-Bacterial Agents↗
PubMed1991

Cryptococcal meningitis in Auckland 1969-89.

Twenty-six patients with cryptococcal meningitis were seen in Auckland between 1969 and 1989. The incidence of cryptococcal meningitis in Auckland residents was 0.12 cases/100,000/year. Ten (38%) of the patients were Maori or Pacific Island Polynesians. Nineteen (73%) had a predisposing cause, including immunosuppressive therapy in nine and the acquired immunodeficiency syndrome (AIDS) in seven. The most common presenting syndrome was a subacute or chronic meningitis. Other clinical syndromes included a slowly progressive ataxia, polyradiculopathy, and headache with vomiting. In two patients, the symptoms of meningitis were overshadowed by those of systemic cryptococcal infection. Delay in making the diagnosis was common. The most sensitive method for diagnosing cryptococcal meningitis was the cerebrospinal fluid cryptococcal antigen test. Antifungal therapy cured 17 of the 25 (68%) treated patients overall, 15 of the 19 (79%) without AIDS and six of the seven with no underlying disease.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The effects of filiform appendage removal on semen collection in the ram.

The effects of removal of the filiform appendage and the type of collection cone used (polyethylene, rubber, Teflon) on the quantity and quality of semen collected from rams were examined. A total of 182 semen collections from six rams (three appendage-intact and three appendage-amputated rams) were utilized in the study. Observations of ejaculated semen distribution and drainage patterns indicated differences between appendage-intact and appendage-amputated rams. A larger volume of semen and a higher number of spermatozoa were collected from amputated than from intact rams (P<0.05). Amputation of the filiform appendage had no effect (P>0.05) on initial motility, thermal stress resistance, or morphology of spermatozoa, regardless of the type of collection cone used. Spermatozoa retained on collection cone surfaces were more sensitive to thermal stress (P<0.05). The morphology of spermatozoa was not affected by type of collection cone (P>0.05). Thus, filiform appendage removal increases ram semen collection efficiency while maintaining semen quality.

Journal Article↗
PubMed1991

Cure of Salmonella hadar endovascular infection with medical therapy.

Endovascular infection due to salmonellae is an uncommon condition with an extremely poor prognosis. We describe a patient with endovascular infection due to Salmonella hadar who was cured by prolonged medical treatment with third generation cephalosporin and fluoroquinolone antibiotics.

Cephalosporins↗
PubMed1990

Efficacy of nicardipine in angina pectoris.

The dose-related efficacy and safety of nicardipine, a new calcium antagonist of the dihydropyridine class, was assessed by exercise tolerance testing in a randomized, double-blinded, placebo-controlled study in 19 patients with chronic, stable effort angina pectoris. Four patients were assigned to each of four treatment sequences receiving nicardipine three times daily in an extended Latin-Square study design. An increase in total exercise capacity, time to onset of angina and time to 1 mm ST segment depression was observed with nicardipine 90 mg/day compared to placebo (P less than .05). Gradual upward dose titration in 30 mg/day increments starting from 30 mg/day appeared to produce maximal increase in exercise capacity. Two patients developed adverse side effects attributable to the drug when administered nicardipine 90 mg/day directly from placebo.

Aged↗
PubMed1989

Human serum antibody responses to Bordetella pertussis infection and pertussis vaccination.

We used an immunoblotting technique to compare the serum antibody responses to pertussis toxin (PT), filamentous hemagglutinin (FHA), a 69-kilodalton (kDa) adenylate cyclase-associated protein (69 KD protein), and Bordetella pertussis outer membrane proteins (OMPs) following either B. pertussis infection or immunization with whole-cell pertussis vaccine. Infection and vaccination induced nearly equally intense antibody responses to PT and to FHA, but vaccination induced stronger antibody responses to the 69 KD protein and to many OMPs. The importance of serum antibody responses to the 69 KD protein and to B. pertussis OMPs other than PT and FHA in conferring immunity to pertussis after vaccination is unknown. Serum antibody responses to PT following either infection or vaccination were almost exclusively to the 28-kDa enzymatic subunit (S1) and only rarely and weakly to the lesser molecular weight binding subunits (S2-S5).

Adenylate Cyclase Toxin↗